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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.

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.

What are contact lenses?

A contact lens (also known simply as a “contact”) is a corrective, cosmetic, or therapeutic lens usually placed on the cornea of the eye. Modern soft contact lenses were invented by the Czech chemist Otto Wichterle, who also invented the first gel used for their production

Contact lenses is also a kind of optical glasses with special glasses lens usually serve the same corrective purpose as conventional glasses like prescription sunglasses but are lightweight and virtually invisible—many commercial lenses are tinted a faint blue to make them more visible when immersed in cleaning and storage solutions.

Some cosmetic lenses are deliberately colored to alter the appearance of the eye.It has been estimated that 125 million people use contact lenses worldwide (2%),including 28 to 38 million in the United States and 13 million in Japan.The types of lenses used and prescribed vary markedly between countries, with rigid lenses accounting for over 20% of currently-prescribed lenses in Japan, Netherlands and Germany but less than 5% in Scandinavia. People choose to wear contact lenses for various reasons. Buy discount eyeglasses , cheap eyeglasses online.

Many consider their appearance to be more attractive with contact lenses than with glasses. Contact lenses are less affected by wet weather, do not steam up, and provide a wider field of vision. They are more suitable for a number of sporting activities.

Additionally, ophthalmological conditions such as keratoconus and aniseikonia may not be accurately corrected with glasses.

Background

Blur is the subjective experience or perception of a defocus aberration within the Eyeglasses. Blur may appear differently depending on the amount and type of refractive error.

The following are some examples of blurred images that may result from refractive errors:
Blur is corrected by focusing light on the retina. This may be done with eye glasses , rimless eyeglasses , lexible eyeglasses or contact lenses, or by altering the shape of various eye structures via refractive surgery or special contact lenses.Eyeglasses sometimes have unwanted effects including magnification or reduction, distortion, color fringes, altered depth perception, etc. You can buy discount eyeglasses , cheap eyeglasses online

Although many people think of lenses as magnifiers, the lenses within eyeglasses improve vision primarily by reducing blur. Depending on the optical setup, they may also produce magnfication or reduction of images which may or may not be intentional or desirable.

Risks Of Wearing Contact Lenses
article source: www.fda.gov

Wearing contact lenses not like wearing discount eyeglasses ,puts you at risk of several serious conditions including eye infections and corneal ulcers. These conditions can develop very quickly and can be very serious. In rare cases, these conditions can cause blindness.You can not determine the seriousness of a problem that develops when you are wearing contact lenses not eyeglass lenses. You have to get help from an eye care professional to determine your problem.If you experience any symptoms of eye irritation or infection,
* remove your lenses immediately and do not put them back in your eyes.
* contact your eye care professional right way.
* don’t throw away your lenses just as eyewear frames. Store them in your case and take them to your eye care professional. He or she may want to use them to determine the cause of your symptoms.
* report serious eye problems associated with your lenses to the FDA’s MedWatch reporting program.

Symptoms of Eye Irritation or Infection
* discomfort
* excess tearing or other discharge
* unusual sensitivity to light
* itching, burning, or gritty feelings
* unusual redness
* blurred vision
* swelling
* pain

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Serious Hazards of Contact Lenses
Symptoms of eye irritation can indicate a more serious condition. Some of the possible serious hazards of wearing contact lenses are corneal ulcers and eye infections.

Corneal ulcers are open sores in the outer layer of the cornea. They are usually caused by infections. You can reduce your chances of infection if:
* you replace your contact lens storage case every 3-6 months
* you clean and disinfect your lenses properly
* you always use fresh contact lens solution and avoid non-sterile water (distilled water and tap water are not sterile and should not be used)
* you never reuse cheap eyeglasses contact lens solution
* you remove your contact lenses before swimming.

Any lenses worn overnight increase your risk of infection. Even lenses that are designed to be worn overnight (extended-wear contact lenses) increase your risk. When worn overnight, contact lenses reduce the amount of oxygen that gets to the cornea. This stresses and damages the surface of the cornea known as the epithelium. Germs can grow more rapidly in stressed corneas.

Other risks of contact lenses include
* pink eye (conjunctivitis)
* corneal abrasions
* eye irritatio

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