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A Cisco Cisco Certification Success Story

Kristen Cianci Job Title and Responsibilities: Network Specialist for the State of Connecticut University System
Certifications Held: Cisco CCNA?
Up Next: Kristen plans on obtaining her CCIE R&S?is currently in the process of recertifying for the CCNP.

Back when hardware upgrades meant adding a CD-ROM drive, soldering new circuits onto motherboards or installing a mouse, Kristen Cianci could be found doing just that. She was a single mom with three little ones, working in her father’s computer shop as a secretary When the shop got behind, she was shown how to do simple upgrades and repairs. She found herself troubleshooting Windows workgroups, supporting small networks and soon moved into field service work. It was 1993, and her IT career was off and running

Kristen first became aware of Cisco while working for a local municipality doing WAN upgrades on Cisco routers. She was a full time professional and active mother, and had no time left for formal classroom training. As a personal challenge, she earned her CCNA and CCNP through diligent self-study, peer mentorship, and practice, practice, practic.”I truly enjoy the troubleshooting aspect of networking,?”Kristen explained.”The challenge of finding a problem and fixing it is a thrill to me. I pursued a Cisco certification because they are the industry leader and all the gear I was upgrading to was Cisco equipment.”

Almost 15 years later, Kristen is a Network Specialist for the Connecticut State University System. She is responsible for fixing network outages, daily monitoring and maintenance, as well as a spearheading assigned networking projects.”Working for the state government in higher education is different from a corporate environment,”she said.”I enjoy the fact that keeping the network up and trouble free directly benefits the students working on their education.”

While she has worked along side other Cisco professionals in the past, she is the only certified individual she is aware of amongst her peers or at work.I have worked with CCIE’s on large projects in the past.Their presence is a huge benefit to any company.I learned a lot working alongside some great engineers.”Kristen is a lifetime learner.always looking ahead and seeking self-improvement through education.”I would love to become a CCIE R&S,” she continued,”and to work for a large support company on large networks. In addition to troubleshooting,I find security and forensics especially interesting.”

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Let’s face it, shopping for eyeglasses can be so much fun, or it can be a hassle. If you think it is a hassle, it probably because you don’t know what shape your face is and which styles of eyeglass frames go well with your face shape. There are a couple of secrets that master opticians have been using for years to quickly and efficiently find the best looking frames for most any face. And that secret is know what shape each and every face is. Good thing for you, you only need to know your own face shape.

You could ask your loved ones what shape your melon is, but be prepared for an unpleasant conversation if you don’t appreciate being called a triangle head when you buy discount eyeglasses and cheap eyeglasses online .

Alternatively, you can easily figure it out for yourself. Grab yourself a pencil and paper and go to the mirror. If you don’t have a pencil and paper handy, you can do this exercise in a steamy mirror or some people will actually draw right on the mirror with lipstick. (If you decide to draw on the mirror with lipstick, remember to clean it up before you have company.)

As you look at yourself in the mirror, ask yourself the following questions. “Is my face taller than it is wide, or is it about even in both directions?”

Next, take a look at your facial curves. Are they mostly angles or are they soft curves? Some face have strong outline features while others are very soft.

Now use your drawing skills. Think about what you just decided your face looked like and draw it out in a shape.

The chances are that the shape you just drew is similar to either a circle, square, oval, or a heart (triangle). In reality, most of our faces can easily be categorized into one of those four face shapes. Certainly we could get more detailed, but there is no purpose to do so when thinking of eyeglasses.

Now when you go to pick out your next pair of glasses look for eyeglasses that directly contrast the shape of your face. If you have strong angles on your face, you will want softer curves on your glasses. Square faces do well with rectangularly rounded shaped frames. If you have a round face, still look for that rectangular shape frame, but only with stronger angles.

Always remember your face shape, it probably won’t change all that much, but your glasses will. Remember the few simple rules of looking for contrasting shapes and you will certainly be able to find plenty of frames that will make you look and feel like the fashionably person you are

Cisco Ccnp Certification

Cisco CCNP exams Certification Outline
(1) 1.1 Introduction
(2) 1.2 Course Objectives Module 2
(1) 2.1 Support Resources
(2) 2.2 Hand-Held Test Equipment
(3) 2.3 Network Monitors
(4) 2.4 CCO ?C Cisco Connection Online
(5) 2.5 Creating a Case
(6) 2.6 Summary Module 3
(1) 3.1 Using Troubleshooting Methods
(2) 3.2 Problem Solving Model
(3) 3.3 Example Lab
(4) 3.4 Introduction to the Equipment
(5) 3.5 Lab ?C Configuration
(6) 3.6 Summary
part two
(1) 1.1 Ticket 001 ?C Physical Layer Connectivity
(2) 1.2 Summary ?C Physical Layer Connectivity. Trouble
(3) 1.3 Ticket 002 ?C Connection Issues
(4) 1.4 Summary ?C Connection Issues
part three
(1) 1.1 Ticket 003 ?C Static to DHCP
(2) 1.2 Summary ?C Static to DHCP
(3) 1.3 Ticket 004 ?C Power Failure
(4) 1.4 Summary ?C Power Failure
part four
(1) 1.1 Ticket 005 ?C ISDN Failure
(2) 1.2 Summary ?C ISDN Failure
(3) 1.3 Ticket 006 ?C Ethernet Switching
(4) 1.4 Summary ?C Ethernet Switching Course Review

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Move Forward to Ccie After Ccnp

Candidates preparing to pass the CCNP exams are putting together Cisco home labs like never before. With CCNA and CCNP home lab equipment, candidates have realized the importance of working on real Cisco routers and switches on the way to earning their CCIE certifications.

One question I get often from CCNP candidates is goes something like this: "I'm planning on pursuing the CCIE after I get my CCNP. What kind of routers and switches should I buy now in order to use the same equipment in my CCIE home lab?"

This is going to sound strange coming from me, because I'm the #1 proponent of CCNA and CCNP candidates buying their own home labs. When it comes to the CCIE, though, I have to say that you're probably better off using rack rentals instead of investing big money now to buy more expensive equipment with which to earn your CCNP Certification.

There are plenty of 2500 and 2600 routers out there that you can buy to prepare fully for your CCNA and CCNP exams that may not have the capability needed for IE preparation. (For instance, while 2500 routers are fantastic for CCNA and NP study, they shouldn't be used for IE study.) The issue with buying more expensive equipment is that Cisco rightfully updates the CCIE lab equipment list twice a year, and these moves can prove very costly for those who get caught in the middle of these changes

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6 Steps to Pass Cisco CCNA Certification Exams

CCNA is one of the most respected Associate level Certification in the world today.
Getting a CCNA will definitely help you to get a better job or at least get your foot into Professional Networking Field. When you meet a person that has CCNA degree you will notice that he or she knows something about Networking.
In the 70-291 exam resources, MCDBA Implementing, Managing, and Maintaining a Microsoft Windows Server 2003 Network Infrastructure, you will cover every field and category in helping to ready you for your successful Microsoft Certification.
In the sy0-101 exam resources, SECURITY+ CERTIFICATION EXAM, you will cover every field and category in helping to ready you for your successful CompTIA Certification.

1. Getting ready mentally:
First thing you need to do is mentally prepare your self. What I mean by that is that you have to seriously think about on why are you getting CCNA and why do you want to be CCNA certified. You have to firmly decide and believe that you will get CCNA within next 3-6 months or so.
Try to budget your study time well. If you a very social person (like me) you will have to give up some of your social time for the next couple of months.
Your friends and family will understand. Trust me: it is well worth it. Once you get that cert you can make up for the lost social time.
In the 70-647 exam resources, Pro:Windows Server 2008, Enterprise Administrator, you will cover every field and category in helping to ready you for your successful Microsoft Certification.
In the 642-901 exam resources, BSCI - Building Scaleable Cisco Internetworks, you will cover every field and category in helping to ready you for your successful Cisco Certification.

2. Getting the right study material:
Second thing you need to do is to get proper study material.
There is lot of controversy around this and some people go overboard with study guides, books, simulators and such.
I believe that two Cisco Press books INTR and ICND by Wendell Odom are enough as far as the books go. They are really well written and easy to follow. So sign up at http://www.ciscopress.com and get those two books. Make sure you got the latest version.You will also want to get some kind of a simulator that will let you practice commands and that will also build up your confidence.You can buy real equipment but that could get expensive. I highly recommend that you become member of Cisco Certification forum.
Forum is huge and you will get lot of helpful answers, tips and advices pretty quick. (I know I did)

3. Approach and diving deep:
There are many different approaches to studying from books but I will tell you about mine. This step will take the most of your studying time.
-Before you even start reading any of the books I suggest learning binary math (really easy) and subnetting so you can do it in your sleep.http//www.examsmarter.com is excellent resource. -read both books casually once from front to cover (make sure you cover introduction and practice questions too). This will give you good overview.
-Install both CD's that came with books and practices some of the questions. Don't worry if you get lot of them wrong.
In the n10-003 exam resources, Network+ Certification Exam, you will cover every field and category in helping to ready you for your successful CompTIA Certification.
-Now, you will ready both books again but this time you will have to read it to truly understand the concept and how things work. Master one chapter and do questions from just that chapter until you sick of it. Then move to the next chapter.
-Once you mastered all chapters do lot of questions and labexercises. Those two CD's will give you ability to do that.

4. Schedule the test:
You're not done yet with studying but it is really good to schedule the test after you completed step 3 in this article. Here is why:If you schedule the test a month in advance right after you completed step 3, you won't be able to slack and make excuses not to study hard until tests and it is also good to give your self a headline. I have seen people working on their CCNA for 2 years. They master one or two chapters, then they rest for 2 two months and right when they think they are ready for the next chapter, they forget what they have learned in the first chapter.

5. Read both books one more time to refresh.
This is optional, but I highly recommend reading the both books one more time. If you read both books in a three week that will give you one more week before the test to cram which is subject of the next step.
So by now you should've read both books three times over. I also suggest re-reading questions and answers from both books one more time.

6. Cram, Cram and Cram -This is the last part of your study and there is no turning back. Deadline is hanging around your neck like a noose. You should cram Q&A for no more then 10 days before you take the test.
At this point it is really important that you get fresh and different questions then those included with your CD's. Some people claims that brain dumps or Q&A are bad and evil. I tend to disagree with that. At this point you already firmly grasped the whole CCNA concept and Q&A will only help you. So get some Q&A exam question and cram, cram and cram them for a week.Don't use books or CD's anymore. There is no looking back. No worries, material from the books will return to you at the right time.

Causes and Treatment of Pink Eye
article source: ezinearticles.com

What is Pink Eye?
Pink eye, also known as conjunctivitis, is swelling and redness of the membranes (conjunctiva) on the inner parts of the eyelid and the eye surface. Pink eye is very common. It is usually not serious, and often goes away in a few days without medical treatment.

What Causes Pink Eye? Is It Contagious?
The leading cause of pink eye is a viral infection, which is highly contagious. Bacteria such as staphylococci, pneumococci, and streptococci cause bacterial pink eye, which is also very contagious. Non-contagious pink eye can result from allergies or exposure to chemical irritants. Rheumatic diseases, Kawasaki’s disease, and certain inflammatory bowel diseases can cause pinkeye. Additionally, dry eyes from lack of tears or exposure to wind and sun can cause pink eye, as can foreign bodies such as dirt or bugs.

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Symptoms of Pink Eye
- Viral conjunctivitis is often caused by an upper respiratory tract infection, and the cold-like symptoms that accompany such viral infections. Discharge is watery, rather than green or yellow.
- Bacterial conjunctivitis is often associated with eye pain, redness, tearing, irritation, and moderate to large amounts of discharge, usually yellowish or greenish in color.
- Allergic conjunctivitis symptoms usually include intense itching, tearing, and swelling of the eye membranes. Other typical allergy symptoms such as sneezing, itchy nose or scratchy throat may also be present.

Treatment Options for Common Pink Eye Infections

Viral Conjunctiva Treatment
Although most viral pink eye will not require antibiotic treatment, sufferers should still see their doctor. This type of pinkeye can be associated with infection of the cornea, which requires early detection and treatment. Symptoms of viral pinkeye can be relieved with cool compresses and artificial tears. In extreme cases, topical steroid drops may be prescribed to reduce discomfort.

Bacterial Conjunctiva Treatment
Antibiotic eye drops or ointments are generally prescribed for bacterial pinkeye. Moderate to large amounts of discharge accumulates during sleep, resulting in the sensation of the eyes being “stuck shut” upon awakening. Applying a damp, warm wash cloth to the eyes, being careful to use a different washcloth for each eye, will remove the discharge.

Allergic Conjunctiva Treatment
Over-the-counter decongestant eye drops can relieve seasonally occurring allergic pinkeye. Cold, moist wash cloths can also be applied to the eyes. Again, care should be taken to use a different cloth for each eye. In extreme cases, a prescription may be necessary.

Tips for Administering Eye Drops to Young Children
Rather than frightening a child by forcing the eye open while the bottle or dropper is plainly visible, try this: ask the child to lie back and close his or her eyes. Place the recommended number of drops in the inner corner of the eye, next to the bridge of the nose. The drops will form a little pool and when the child’s eyes open, the drops will flow gently into the infected areas without a fuss.

Considering Lasik Surgery? Lasik Eye Surgery Can Improve Your Sight
article source: ezinearticles.com

Lasik Surgery is a surgery that is performed by Ophthalmologists. It is often painless and quick. The good thing is that the patient can go back to work with immediate effect after the Lasik Surgery is performed, sometimes as early as the next day. The ability of the surgeon combined with the high-level technology that is required for the surgery is what ensures that the operation is successfully performed and completed.

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Many patients prefer Lasik Surgery and think that they would rather undergo a Lasik Surgery than wear glasses or contact lenses. The Lasik Surgery takes a pretty short time because of the uniqueness of the surgery. The surgery never takes more than eight to ten minutes. Since Lasik Surgery is Laser Surgery, it involves the burning of tissues. The laser gets to the tissue by burning the stroma and it does not take long for the eye to “recover” because unlike other surgeries, here the tissue is not “hurt” in any way.

Lasik Surgery is a quick procedure, it only takes about an hour– but patients are asked to take rest for longer. One must avoid the urge to scratch the eye during this time. The patient may have the propensity to do so because the eye is exceedingly irritable at this juncture. The patient must avoid plunging into swimming pools and other water sports that he/she might be interested in for a month. Dry eyes and Halo may be caused because of this process.

When you compare the Lasik Surgery to other kinds of surgeries, you understand that it is free from most of the trouble that most other surgeries cause. Still, it is advisable to take all the precautions that are necessary to avoid any infection or complications later on. The patient must not use any lotions or any make-up for about two days after the surgery as that might hamper the patient’s speed of recovery. Also, sports like Karate, Kick Boxing, and Taekwondo should be played only after complete recovery.

For a laser Eye surgery, one must choose his/her doctor very carefully. For a sensitive operation like this, it is very important to realize that one’s eye is one’s asset and one cannot afford to take any chances. While some doctors may perform the surgery at a cheaper cost, it is always better to go with a doctor who has experience and who has performed these surgeries successfully before.

Who benefits from a Lasik Surgery?
Anyone with poor eyesight benefits from Lasik Surgery. Since this is a refractive laser eye surgery, ophthalmologists use it to cure myopia, astigmatism, and hypermetropia. However, if not performed carefully the patient can suffer from substantial loss of contrast sensitivity.
The decision for a Lasik Surgery should be taken after consulting one’s doctor. After all, this is a risk of sorts and comes with its fair share of side effects. If none of the doctors you know have ever done Lasik Surgery (and this is possible because it is a fairly new kind of surgery), then it is best to go to a large and reputed clinic before you decide to go in for a Lasik Surgery.

In 2006, a study was done that concluded that contact wearers are at a greater risk for infection than individuals who have had Lasik eye surgery

Eye Problems in Children

Each Child is important to an individual family. It is but natural that parents become anxious if there is any problem to any of the organs of the child. As the eyes are important and very precious, they would be concerned if their daughter or son has eye problems and to buy discount eyeglasses cheap eyeglasses or other eyeglasses online.

There are many eye problems that are commonly found in children. The major problem is the refractive error, the common mode of presentation is that the child is not able to see the distant objects usually seen in the school where the child fails to see clearly the letters written by the teacher on the blackboard. Most of the time the child holds the book very close to the eyes while reading. And also child watches TV with reading eyeglasses and Computers from a very close distance.
The other problems are – Vitamin A deficiency, Squint eyes and Retinoblastoma (Eye Cancer).

Refractive Errors:
There are mainly three types of refractive errors. Myopia, Hypermetropia and Astigmatism.

Myopia : This is the most common refractive error found in children. Usually it is detected when the child is having problem in seeing distant objects. Occasionally the child may have a slight pain in the eyes after reading for many hours. The light rays are focused in front of the retina in myopia with the result that the objects appear hazy.( If we have to see a clear object it has to be focused on the retina.) Sometimes it has a strong family history. The eye has to be properly examined by a competent Ophthalmologist (not by an Optometrist) and suitable glasses prescribed at the earliest. Regular follow - up is also a must in these children.
Astigmatism is another refractive error seen in children not as frequently as Myopia. Hypermetropia where the child has + numbers in glass, is comparatively less in frequency. Suitable eyeglasses correct both these refractive errors.

Vitamin A Deficiency:
Vitamin A Deficiency is demonstrated in school going children. Usually children in the age group of 6-12 years complain of night blindness. In other words those children have inability in seeing objects clearly in dim light. Sometimes small pigmented patches are seen by the side of the cornea. These are called Bitot’s spots. At this stage the child has lot of watering in the eyes.

A substance called visual purple has to be created in the retina to visualize objects clearly in the dim light. Vitamin A is necessary to create this object. When there is deficiency of Vitamin A in the diet, child gets night blindness. Sometimes some skin problems are associated along with eye problems.
Vitamin A deficiency is treated by giving capsules of Vit.A 2500-5000 IU or 750 mg of beta-carotene. In severe cases injections may be needed. Green leafy vegetables, carrots, milk, curd, butter, egg, liver etc., have rich contents of Vitamin A.

Squint Eyes : The two eyes normally should be in a definite visual axis. A manifest deviation of the visual axis of either eye is known as squint or strabismus. Mainly there are two types of squints – Paralytic and Non-paralytic or Concomitant. Concomitant is the one which is mostly seen in children. Concomitant deviations are for the most part, produced by anomalies of the power of convergence and divergence and the co-ordinated use of the two eyes to obtain binocular single vision. In these cases the amount and character of the deviation does not vary when the eyes are turned to the right or left.

The other classification of squint is – Convergent and Divergent. Convergent squint is the one in which one of the eye is turned inside, whereas in divergent squint one of the eye is turned outside.

Each child with squint has to be properly investigated before undertaking treatment. The common methods of treatment are – 1) Correcting the refractive errors by glasses whenever that is found to be the cause of the squint. 2) Deliberate occlusion or patching of the fixing eye so as to improve the vision of the squinting eye. 3) Suggesting special type of ( Orthoptic) exercises to improve the binocular faculties. 4) By surgery to restore parallelism of the visual axis. One or more of these methods or all four may be needed.

Retinoblastoma: It is the cancer or malignant tumor of the eye , usually seen in children below 5 years. It may be seen at birth or later. This disease not only affects the vision, but also life itself if it is not diagnosed and treated properly at an appropriate time. It may be seen in one eye or both.
Usually the child is brought to the eye specialist with the complaint that something white or yellow material is seen in the eye. If one eye is swollen enormously, it is understood that the disease is advanced. Treatment is usually removal of the eyeball as soon as the disease is diagnosed and the cut portion sent for biopsy. After the removal of the eyeball, if there are any signs of the disease,

Radiotherapy is advised. At this stage the other eye is examined and if any traces are found it is also subjected to radiotherapy. In the advanced stage of the disease, it is mandatory to treat with chemotherapy.
Apart from these eye injuries, congenital cataract and glaucoma are the other diseases of children. Parents and teachers have great responsibility in the proper management of the eye diseases

Children’s Eyeglasses and the Six Musts to Buying Them
article source: ezinearticles.com

Many parents dread walking into an optical store in search of buying a pair of eyeglasses for their children. Not only is it a pain at time but it also can be a little confusing. There are so many children’s eye glass frames to choose from that even finding a starting point is difficult, but that’s only of the problems. What about deciding which ones your child would actually enjoy wearing or what frame will last longer than a few days?

Another problem us children’s eye glasses come in so many different styles and kid-friendly colors anymore. My answer to this is to let your child choose a few they like and then use those few as a base to make your selection. Let’s face it, the more they the pair of glasses they have, then the more likely it is that they will wear them.

Try asking your eye doctor to give you some specific recommendations about finding eyeglasses frames. The decision doesn’t need to be yours and yours alone. To help you out in deciding what to look for in a pair of eyeglasses, here are five rules to follow in your search:

* Scratch-resistant coating - The normal polycarbonate lenses that most people get their glasses made from contain a resistant coating already, but it is a good idea to upgrade to the heavy duty scratch-resistant coating for your kid’s glasses eyewear. This extra tough coating gives an even stronger resistance to possible scratching. Another plus with this type of coatings is the better warranty it comes with. Just be aware that no lenses are scratch proof especially when kids are involved.
* Spring hinges - The idea behind spring hinges is the flexibility they give the frame to bend outward when your child is putting on or taking off their glasses. Most kids just yank them right off their face instead of slowly with two hands. Actually most kid’s glasses break from this.
* Silicone nose pads - We’ve all seen these pads. They are what keep your glasses from falling down your face. The ones made from silicone are great for children because they tend to be soft and much more comfortable.
* Tinting - Most eye doctors do not recommend to buy glasses like tinting children’s glasses because it can be harmful to their eyes. Instead, look into photo-chromatic lenses as an alternative. These will automatically darken outside in the sunlight while lightening up as they come back into less lighted areas such as indoors. If these lenses are too expensive, another alternative is to just purchase a pair of clip-on tinted lenses attached to the frame.
* Warranties - Warranties for glasses usually vary from place to place especially when it comes to children’s glasses. You are in good shape if you can fine a warranty on a frame that runs for at least one year after the date of purchase. Anything longer than that is unneeded since the child will just outgrow the lenses or the frames.

Types of contact lenses:By wear time

A daily wear contact lens is designed to be removed prior to sleeping. An extended wear (EW) contact lens is designed for continuous overnight eye glasses, typically for 6 or more consecutive nights. Newer materials, such as silicone hydrogels, allow for even longer wear periods of up to 30 consecutive nights; these longer-wear lenses are often referred to as continuous wear (CW). Generally, extended wear lenses are discarded after the specified length of time. These are increasing in popularity, due to their obvious convenience. Extended- and continuous-wear contact lenses and titanium eyeglasses can be worn for such long periods of time because of their high oxygen permeability (typically 5-6 times greater than conventional soft lenses), which allows the eye to remain healthy.
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Extended lens wearers may have an increased risk for corneal infections and corneal ulcers, primarily due to poor care and cleaning of the lenses, tear film instability, and bacterial stagnation. Corneal neovascularization has historically also been a common complication of extended lens wear, though this does not appear to be a problem with silicone hydrogel extended wear. The most common complication of extended lens use is conjunctivitis, usually allergic or giant papillary conjunctivitis (GPC), sometimes associated with a poorly fitting contact lens.

Types of contact lenses:By constructional material

Contact lenses,other than eyeglasses and the cosmetic variety, become almost invisible once inserted in the eyeThe first contact lenses were made of glass such as rimless eyeglasses, flexible eyeglasses and which caused eye irritation, and were not wearable for extended periods of time. But when William Feinbloom introduced lenses made from polymethyl methacrylate (PMMA or Perspex/Plexiglas), contacts became much more convenient. These PMMA lenses are commonly referred to as “hard” lenses (this term is not used for other types of contacts).

However, PMMA lenses have their own side effects: no oxygen is transmitted through the lens to the cornea, which can cause a number of adverse clinical events. In the late 1970s, and through the 1980s and 1990s, improved rigid materials — which were also oxygen-permeable — were developed. Collectively, these polymers are referred to as rigid gas permeable or ‘RGP’ materials or lenses. One advantage of hard lenses is that, due to their non-porous nature, they do not absorb chemicals or fumes. The absorption of such compounds by other types of contacts can be a problem for those who are routinely exposed to painting or other chemical processes.

Rigid lenses offer a number of unique properties. In effect, the lens is able to replace the natural shape of the cornea with a new refracting surface. This means that a regular (spherical) rigid contact lens can provide good level of vision in people who have astigmatism or distorted corneal shapes as with keratoconus.

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While rigid lenses have been around for about 120 years, soft lenses are a much more recent development. The principal breakthrough in soft lenses made by Otto Wichterle led to the launch of the first soft (hydrogel) lenses in some countries in the 1960s and the approval of the ‘Soflens’ material (polymacon) by the United States FDA in 1971. Soft lenses are immediately comfortable, while rigid lenses require a period of adaptation before full comfort is achieved. The polymers from which soft lenses are manufactured improved over the next 25 years, primarily in terms of increasing the oxygen permeability by varying the ingredients making up the polymers.

A small number of hybrid rigid/soft lenses exist. An alternative technique is piggybacking of contact lenses, a smaller, rigid lens being mounted atop a larger, soft lens. This is done for a variety of clinical situations where a single lens will not provide the optical power, fitting characteristics, or comfort required.

In 1999, ’silicone hydrogels’ became available. Silicone hydrogels have both the extremely high oxygen permeability of silicone and the comfort and clinical performance of the conventional hydrogels. These lenses were initially advocated primarily for extended (overnight) wear, although more recently daily (no overnight) wear silicone hydrogels have been launched.

While it provides the oxygen permeability, the silicone also makes the lens surface highly hydrophobic and less “wettable.” This frequently results in discomfort and dryness during lens wear. In order to compensate for the hydrophobicity, hydrogels are added (hence the name “silicone hydrogels”) to make the lenses more hydrophilic. However the lens surface may still remain hydrophobic. Hence some of the lenses undergo surface modification processes which cover the hydrophobic sites of silicone. Some other lens types incorporate internal rewetting agents to make the lens surface hydrophilic.

Types of contact lenses:By design

A spherical contact lens is one in which both the inner and outer optical surfaces are portions of a sphere. A toric lens in cheap eyeglasses is one in which either or both of the optical surfaces have the effect of a cylindrical lens, usually in combination with the effect of a spherical lens. Myopic (nearsighted) and hypermetropic (farsighted) people who also have astigmatism and who have been told they are not suitable for regular contact lenses may be able to use toric lenses. If one eye has astigmatism and the other does not, the patient may be told to use a spherical lens in one eye and a toric lens in the other. Toric lenses are made from the same materials as regular contact lenses but have a few extra characteristics than other glasses like plastic frames They correct for both spherical and cylindrical aberration.
They may have a specific ‘top’ and ‘bottom’, as they are not symmetrical around their centre and must not be rotated. Lenses not in metal frames must be designed to maintain their orientation regardless of eye movement. Often lenses are thicker at the bottom and this thicker zone is pushed down by the upper eyelid during blinking to allow the lens to rotate into the correct position (with this thicker zone at the 6 o’clock position on the eye). Toric lenses are usually marked with tiny striations to assist their fitting.

They are usually more expensive to produce than non-toric lenses in discount eyeglasses ; therefore they are usually meant for extended wear. The first disposable toric lenses were introduced in 2000 by Vistakon.
Like eyeglasses, contact lenses and sunglasses online can have one (single vision) or more (multifocal) focal points.

For correction of presbyopia or accommodative insufficiency multifocal contact lenses are almost always used; however, single vision lenses may also be used in a process known as monovision[32]: single vision lenses are used to correct one eye’s far vision and the other eye’s near vision. Alternatively, a person may wear single vision contact lenses to improve distance vision and reading glasses to improve near vision.

Rigid gas permeable bifocal contact lenses most commonly have a small lens on the bottom for the near correction, when the eyes are lowered to read, this lens comes into the optical path. RGPs must translate (move vertically) to work properly, and thus the gaze of the eye can change from the near to the distant sections, much like bifocal eyeglasses.

Multifocal soft contact lenses are more complex to manufacture and require more skill to fit. All soft bifocal contact lenses are considered “simultaneous vision” because both far and near vision corrections are presented simultaneously to the retina, regardless of the position of the eye. Of course, only one correction is correct, the incorrect correction causes blur. Commonly these are designed with distance correction in the center of the lens and near correction in the periphery, or vice versa.

Types of contact lenses:By frequency of replacement

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The various soft contact lenses available are often categorized by their replacement schedule. The shortest replacement schedule is single use (daily disposable) lenses, which are disposed of each night. These may be best for patients with ocular allergies or other conditions, because it limits deposits of antigens and protein. Single use lenses are also useful for people who use contacts infrequently, or for purposes (e.g. swimming or other sporting activities) where losing a lens is likely. More commonly, contact lenses are prescribed to be disposed of on a two-week or monthly basis.

Quarterly or annual lenses used in reading eyeglasses of titanium frames or metal frames , which used to be very common, have lost favor because a more frequent disposal schedule allows for thinner lenses and limits deposits. Rigid gas permeable lenses are very durable and may last for several years without the need for replacement. PMMA hard lenses were very durable, and were commonly worn for 5 to 10 years.

What should be considered when you choose contact lenses?

When you are choosing contact lenses, not eyeglass frames , optical eyeglasses , many factors should be considered including your lifestyle,health,astigmatism,corneal curvature,allergies,dry eyes,hygiene,previous over-wear,frequency of use and so on.Seeing your Optometrist will help you determine the best type of contact lenses for your eyes.

1. A Good Eye Health?
Before you decide to wear contact lenses, not classic eyeglasses or bifocal eyeglasses , you should cheak for your eye health.You can wear only if you have a good health.The healthiest type of lens is the daily disposable soft lens. These lenses are always sterile when inserted into the eyes as they are never kept overnight. This means that no dirt, bugs or tear proteins can accumulate which all have the potential to cause problems. Fortnightly and Monthly disposables are also available which still require daily cleaning and overnight storage with contact lens solutions.

2. Have Astigmatism?
Normally,your eye is shape like a tennis ball.But with astigmatism,your eye is not perfectly round like a tennis ball.At a certain level of astigmatism the contact lens prescription needs to be “tailor-made” in order for you to see clearly. Lenses that cater to astigmatism are called Torics and are available in both rigid and soft form.
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It is often possible to fit a normal rigid contact lens and correct the problem without the need for a Toric with lower levels of astigmatism.If you have mainly short or long-sight with very little astigmatism, a normal soft contact lens is generally fine for you just.

3.What are lifestyle?
Your lifestyle often determines your the requirements of sight correction, which in turn influences the type of contact lens suitable.And if you may work in an office and use the computer all day, for which you wear spectacles; perhaps you play golf, or football once per week and find that your spectacles “steam up”?A limited supply of daily disposables just for sport would be your best option rather than monthly disposables, which require cleaning and will not be used often enough to make them worthwhile.
If you are a rugby player and require good side vision in order to perform optimally, full-time contact lens wear is probably your wisest option.
Frequent jet-setters may prefer spectacles as contact lenses inevitably dry out whilst flying. Whatever your lifestyle, your optometrist will prescribe contact lenses tailored to your needs

4.Have Any Allergies?
Hayfever, eczema or asthma sufferers may find contact lenses more uncomfortable than most people. Allergies can create an over-sensitized eye, rendering increased lens awareness. Also, the eye reacts to dirt and proteins on the lens much more and may cause the upper eyelid to develop bumps. This is called contact lens related papillary Conjunctivitis. The best solution for those with severe allergies is to wear lenses infrequently (up to 3 times/week) and to use daily disposables. If your lifestyle requires you to use lenses constantly, then disposables are still the best option. Occasionally some individuals are allergic to a certain lens material or a certain lens solution.

5.With Dry Eyes?
If you suffer from chronic dry, smarting eyes. It may cause increased lens awareness after some hours of lens wear. Your optometrist will prescribe an alternative lens with a different water content, fitting or material, in order to improve the comfort. Preservative-free contact lens comfort drops are also advised.

6.Your Frequency Of Use.
Are you only wish to use contact lenses for a sporting activity once per week? If you are,a daily disposable will be most suitable from both a health and cost perspective. Rigid lenses are not recommended as they need to be used most days in order to achieve best comfort. Those who wear their lenses sporadically may wish to consider fortnightly or monthly disposables. Your optometrist will be able to discuss the various options most suited to your requirements.

7.Your Previous Over-wear
If you have previously over-worn your contact lenses, your eyes will need more oxygen.So you may be told to use a higher water content, or higher Dk, lens.Because it may be a soft or rigid lens. Remember to give your eyes a break and use your spectacles one day per week.Just remember.

8.Other factors
Such as corneal curvature,hygiene and so on to be considered.