A Contact Lens Exam, Fit, & Follow Up:


If you wear or want contacts, you need a contact lens exam in addition to a comprehensive eye exam. An eyeglass prescription is no substitute for a contact lens exam because the two are very different. An eyeglass prescription measures for lenses that are positioned approximately 12 millimeters from your eyes; whereas a contact lens prescription measures for lenses that sit directly on the surface the eye. An improper fitting or prescription of contacts can damage the health of the eyes.


The contact lens exam includes a number of tests that are not part of a routine health check.


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. You may be asked general questions about your lifestyle and preferences regarding contact lenses, such as how often you want to wear them, if you're going to be using them for sports, if you want/need to be able to sleep in them, your general level of hygiene, or whether you might want to change your eye color with color 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 in your eye and provide sharper vision.


  • To correct presbyopia, your Doc may offer you the choice of multifocal or bifocal contact lenses. Another option is monovision, which is a special contact lens fitting technique where one eye is corrected for distance vision and the other eye is corrected for near vision.

These types of contact fits often require follow ups! Our Licensed Dispensing Opticians perform a test called an Over Refraction that helps them work with Doc to provide the best vision possible for you.


  • Your eye doctor may also discuss the option of rigid gas permeable (RGP or GP) contact lenses, which often provide sharper vision than soft lenses.


Contact Lens Measurements


Just as one shoe size doesn't fit all, one contact lens size doesn't fit all.


If the curvature of a contact lens is too flat or too steep for your eye's shape, you could experience discomfort or even damage to your eye.


A contact lens Exam, Fit, & Follow Up includes:


  • A tear film evaluation is done to determine how moist your eyes are. This test involves adding fluorescein dye to the tear layer on your eye via eye drops and then evaluating how long it takes for your tears to evaporate.


If you have a severe dry eye condition, you might have to avoid or discontinue contact lens wear. But in cases of contact lens discomfort due to mild dryness, special contact lenses for dry eyes may enable you to wear contacts safely and comfortably.


  • Cornea measurements. An instrument called a keratometer will be used to measure the curvature of your eye's clear front surface (cornea). Our tech takes these measurements during the first step of your exam.


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.


  • 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.


The slit lamp also is used to evaluate the fit of a trial contact lens, because it enables your doctor to observe the alignment and movement of the lens as it rests on the surface of your eye.


With the results of those tests, your eye doctor will fit you with a trial pair of contacts and have you wear them for a few days. If they aren’t providing you with clear vision or are uncomfortable, you should report your experience to the Doc or one of the Licensed Dispensing Opticians. They will help tweak the power, fit, or moistness level until you are happy with your contacts.


After finding contact lenses that fit properly, are comfortable for you, and provide good vision, your eye doctor can write your contact lens prescription.


This prescription will designate contact lens brand, power, the base curve (the shape matching the curvature of your eye), diameter, add (if you are getting multifocal lenses), and color (if you are getting color contacts).