Eye exams for contact lenses include special tests that typically are not performed in routine eye exams for eyeglasses.
What To Expect During A Contact Lens Fitting
During your comprehensive eye exam, your visual acuity will be tested using an eye chart, and a number of tests will be performed to determine your eye health and whether prescription eyewear is required to correct refractive errors.
After this testing has been completed, your eye doctor will gather additional information so you can be fitted with contact lenses.
Your eye doctor also might ask how you want to correct vision problems related to ageing. Sometime after age 40, you will develop a condition known as presbyopia that decreases your ability to read the small print and focus on near objects.
Contact Lens Measurements
Just as one shoe size doesn’t fit all, one contact lens size doesn’t fit all.
Cornea measurements. An instrument called a keratometer will be used to measure the curvature of your eye’s clear front surface (cornea).
The keratometer analyzes light reflections from your cornea and determines the curvature of your eye’s surface. These measurements help your eye doctor choose the proper curve and size for your contact lenses.
If your eye’s surface is found to be somewhat irregular because of astigmatism, you may need a special design of lens known as a toric contact lens that is shaped to offset distortions of your eye to provide sharper vision.
Pupil and iris measurements. The size of your eye’s pupil may also be measured. In a simple approach, a card or ruler showing different pupil sizes is held next to your eye to determine the best match.
Evaluation of your eye’s surface and contact lens fit. The health of your cornea will be evaluated using a biomicroscope (also called a slit lamp). This lighted instrument provides a highly magnified view of the cornea and other tissues to enable your eye doctor to evaluate the health of the front of your eyes and detect any changes caused by contact lens wear.
Keep in mind that if you wear contact lenses, your annual eye exams typically will cost more than a routine exam for someone who doesn’t wear contacts, due to the additional contact lens-related tests that are included.