There are many choices in contact lenses these days, so your eye doctor will listen carefully and choose the lens that will best meet all your needs. Your eye doctor will administer various tests designed to evaluate your eyes for contact lens wear. One important test is corneal topography, a test that maps out the different aspects of your cornea. Corneal topography displays results in a way that is very similar to the topography of mountains.
The test results in a map of colors - reddish colors display steeper areas of the cornea, and bluish colors describe flatter areas. Another important test is the slit lamp examination. The slit lamp exam is generally performed during a regular eye examination, however, your eye doctor will spend more time doing a slit lamp examination for a patient who wears contact lenses.
Sometimes eye health problems are diagnosed during this test, and they need to be treated before the contact lens fitting can proceed. Your eye doctor will discuss different contact lens options with you, and once you decide on which ones will be best, you will try on diagnostic contact lenses.
Your eye doctor will administer another slit lamp examination to determine if the lenses fit properly. Finally, a visual acuity test will be performed to determine how well a contact lens corrects your vision. Once the contact lens fitting is complete, if you've never worn contact lenses, your doctor will teach you how to insert, remove and disinfect the lenses.
Hygiene, cleanliness, and disinfection are essential for successful contact lens wear. Your doctor will probably ask you to wear the contact lenses for a week before returning for a follow-up visit.
At your follow-up visit, your doctor will recheck the fit of the contact lenses, and ask about your vision and any problems you may be experiencing. At this point, your eye doctor will try fitting you with a new lens, or finalize your prescription.
If you are dissatisfied with your vision or the comfort of the lenses, your eye doctor will schedule additional follow-up visits. Certain lenses, such as toric lenses for correcting astigmatism or multimodal lenses for correcting presbyopia, can take additional time to achieve a comfortable fit.
Just as one shoe size doesn't fit all feet, one contact lens size doesn't fit all eyes. If the curvature of a contact lens is too flat or too steep for your eye's shape, you may experience discomfort or even damage to your eye.
Measurements that will be taken to determine the best contact lens size and design for your eyes include:. No matter how comprehensive the eye exam for contact lenses, most eye doctors will give you a set of trial lenses just to confirm that they are the right choice for your eyes.
With lenses in place, your doctor will use the slit lamp to evaluate the position and movement of the lenses as you blink and look in different directions. You will also be asked how the lenses feel. Most people wear trial lenses for at least 15 minutes so that any initial excess tearing of the eye stops, and your tear film stabilizes.
Then, you will learn about how to care for your lenses and how long to wear them. You will also receive training on how to put in and take out your new lenses. While it may seem difficult at first, most people quickly learn how to use contacts lenses. After finding a contact lens that fits properly, is comfortable for you and provides good vision, your doctor will then be able to write a contact lens prescription for you.
This prescription will designate the contact lens power, the curvature of the lens called the base curve , the lens diameter, and the lens name and manufacturer. In the case of GP contact lenses, additional specifications may also be included. Your contact lens fitting will involve a number of follow-up visits so your doctor can confirm the lenses are fitting your eyes properly and that your eyes are able to tolerate contact lens wear.
A dye like the one used to evaluate your tear film may be used to see if the lenses are causing damage to your cornea or making your eyes become too dry.
Often, your doctor will be able to see warning signs before you are aware a problem with your contact lens wear is developing. If such warning signs are evident in your follow-up visits, a number of things may be recommended, including trying a different lens or lens material, using a different lens care method, or adjusting your contact lens wearing time.
In occasional cases, it may be necessary to discontinue contact lens wear altogether. Regardless of how often or how long you wear your contact lenses, your eyes should be examined at least once a year to make sure your eyes are continuing to tolerate contact lens wear and show no signs of ill effects from the lenses.
Patients often wonder why a contact lens examination costs more than a regular eye exam. The reason is that fitting patients with contacts lenses involve additional tests and time see the section on contact lens fittings. Expertise is required when fitting contact lenses, as this skill is both a science and an art. These factors are in addition to the tests that are part of a regular comprehensive eye health and vision examination. Each patient has individual eye anatomy, eye health, prescription type and needs, which makes contact lens evaluations and fittings unique for each patient.
To wear or not to wear contact lenses has been hotly debated for a long time. There are many doctors and patients who believe strongly in the benefits of contact lenses, and there are many who would believe the disadvantages and risks definitely outweigh the positives. The benefits and risks can be debated, but the fact is that more than a hundred and fifty million people wear contact lenses in the world today.
While that number is much smaller compared to the number of people wearing glasses, but it is a substantial figure. People suffering from Myopia or nearsightedness, or astigmatism, are often happier with contact lenses. Farsightedness or hypermetropia is a condition that is often better treated with eyeglasses. The different problems in your vision should be considered while debating the pros and cons of contact lenses. Aesthetics plays a big part in the contact lens versus eyeglasses decision.
However, not everyone agrees on who looks better with glasses, or contact lenses. Some people like the idea of changing their eye color with contacts. Do note that some contacts are FDA-approved for overnight wear. So if you want to sleep with your lenses on, ask your eye doctor about extended wear contact lenses.
You may also be wondering if you can participate in water activities like swimming while using your trial lenses. Any time water gets in your eye , it can introduce bacteria, which may cause infections.
Normally, your eyes stay healthy thanks to their natural cleaning system. However, contact lenses increase the chance of infection. A contact lens can hold that bacteria on your eye for a longer period of time. The risk is further complicated if you continue using the same lens, especially if you don't clean it well. The bottom line is that yes, you can wear your trial contact lenses when you go out on the water. Another possibility is if you have daily disposables.
That way, you can throw the lenses out after use. Either way, the risk of infection is increased when you wear contacts in the water, so why take the chance? Now you know a little bit more about what to expect with your trial contact lenses. Contacts are a great way to carry out your daily activities. It's a big world out there, and you want to see it clearly!
You need a steady supply of oxygen to your eyes, day and night, to keep them healthy. Napping or sleeping in daily wear lenses decreases the amount of oxygen flowing to your corneas.
Home Contact Lenses Other Contacts. By Allie Johnson. Schedule an exam Find Eye Doctor. Some lenses last for as little as a single day. Others last for up to two weeks, one month, or a year at a time.
In general, hard contact lenses last longer than disposable, soft contacts do. The lifespan of the lenses will depend on the type you opt for. Your prescription and the brand of lenses you choose will also be contributing factors. Not only do they correct your vision, but they also allow oxygen flow to your eye.
The plastic used to make contacts isn't the type found in food product containers, toys, or even industrial machinery. Contact lenses consist of a hydrophilic plastic that stays soft, provided they are in a moist environment.
In addition to plastics, some contact lenses also include silicone-hydrogel. This is a material that has high oxygen transmission to the eye due to its moisture content. This is why contact lens wearers store their lenses in a special solution when not using them. Otherwise, they will dry up, becoming rigid and useless. While you wear your contacts, your eyes keep them moist.
These lenses would last much longer than the disposable type of contacts we have today, although RGP and PMMA lenses are still available.
In most cases, these lenses last anywhere from a month to a year.
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