Contact Lens Fitting
Fitting Your Contact Lenses
After your eyes have been examined and deemed in need of correction, you’ll receive a prescription for corrective lenses. These lenses could be eyeglasses or contact lenses. If you choose contact lenses, they must be properly fitted. Although not a complex process, it is critical to have your contacts fit correctly, both for your comfort and for the health of your eyes. Here’s how the process works.
You’ll first choose your lens type
There are myriad choices in modern contact lenses, so after we perform your initial exam, we’ll discuss some of your preferences and lifestyle needs. You can choose between soft and hard contacts, although most people now choose soft lenses. You’ll decide if you want to replace those lenses on a daily basis or wear them for more extended lengths of time. You’ll even decide on the color. Modern contacts allow you to change the color of your eyes with the lenses you wear.
If you need bifocals to correct for both near and far vision, you can do that with today’s contacts. There are multifocal contact lenses or you may opt for monovision, where one contact lens corrects your distance vision and the other corrects your near vision.
A variety of measurements will be taken to ensure a precise lens fit
Not all eyes are the same, even within the pair of a single person. Some eyes are more round, others more flat. Some eyes have astigmatism (this used to preclude the person from wearing contact lenses but no longer), which will require lenses that have a top and a bottom to stay properly aligned on the eye. Because of eye variations, precise measurements will be needed to properly fit your contact lenses.
Mapping of the cornea
The doctor will make a detailed map of the surface of your cornea, the eye’s clear front surface. This is called corneal topography and creates a map with the different contours of your eyes.
A keratometer is used to measure the curvature of the cornea, so your contacts match your unique curve and diameter.
Pupil and iris size
A biomicroscope, also known as a slit lamp, is used to measure the size or your pupil and iris. This is especially important if you have opted for hard contacts.
If your eye shape is somewhat irregular because of astigmatism, measurements are made for “toric” lenses that are put into the eyes at a certain angle. Usually these lenses have a mark that needs to be oriented toward the top of your eye.
If you have a condition known as dry eyes, you’ll need to be tested to see if your eyes produce an adequate tear film to keep your lenses sufficiently hydrated. A dye is used for this test. If your tear supply is too low, contacts will not be an option for vision correction.
You’ll demo a pair or two of lenses
Usually, with the wide variety of available lenses, you’ll try a pair or two. The doctor will likely recommend a couple options, giving you the characteristics of each. You’ll then put the lenses in and your eyes will be viewed with the slit lamp to see how they are positioning themselves on your eyes and how they move when you blink and move your eyes in different directions. Once this is done, you may be asked to wear the lenses for a couple days to see if you like their feel. Or, if the fit looks off, another trial pair will be tried.
Satisfied that you have the pair that feels right, you’ll be given instructions on how to insert your lenses, how to care for them, how long to wear them, proper eye hygiene, and other details. And then you’ll be off to a future of clear, comfortable vision.