For many people, contact lenses provide greater convenience and more satisfying vision correction than eyeglasses. Today there are even contact lenses specifically for children.
This is an overview of what’s involved in a typical contact lens exam and fitting.
A comprehensive eye exam comes first
Before being evaluated for contact lenses, a comprehensive eye exam is performed by our eye doctor in Colorado Springs, CO. In this exam, our eye doctor determines your prescription for corrective lenses (just a glasses prescription at this point) and checks for any eye health problems or other issues that may interfere with successful contact lens wear.
If all looks good during your eye exam, the next step is a contact lens consultation and fitting.
What to expect during a contact lens evaluation
The first step in a contact lens evaluation is a consideration of your lifestyle and your preferences regarding contact lenses, such as whether you might want to change your eye color with color contact lenses or if you’re interested in options such as daily disposables. Although most people choose soft contact lenses.
If you are over age 40 and need bifocals, our eye doctor or contact lens specialist will discuss ways to deal with this need, including multifocal contact lenses and monovision (a prescribing technique where one contact lens corrects your distance vision and the other lens corrects your near vision).
Contact lens measurements
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:
- Corneal curvature: An instrument called a keratometer is used to measure the curvature of your eye’s clear front surface (cornea). This measurement helps your doctor select the best curve and diameter for your contact lenses. If your eye’s surface is found to be somewhat irregular because of astigmatism, you may require a special lens design of lens known as a “toric” contact lens. At one time, only gas permeable contact lenses could correct for astigmatism. But there are now many brands of soft toric lenses, which are available in disposable, multifocal, extended wear and colored versions.
In some cases, a detailed mapping of the surface of your cornea (called corneal topography) may be done. Corneal topography provides extremely precise details about surface characteristics of the cornea and creates a surface “map” of your eye, with different contours represented by varying colors.
- Pupil and iris size: The size of your pupil and iris (the colored part of your eye) can play an important role in determining the best contact lens design. These measurements may be taken with a lighted instrument called a biomicroscope (also called a slit lamp) or simply with a hand-held ruler or template card.
- Tear film evaluation: To be successful wearing contact lenses, you must have an adequate tear film to keep the lenses and your cornea sufficiently moist and hydrated. This test may be performed with a liquid dye placed on your eye so your tears can be seen with a slit lamp, or with a small paper strip placed under your lower lid to see how well your tears moisten the paper. If you have dry eyes, contact lenses may not be right for you. Also, the amount of tears you produce may determine which contact lens material will work best for you.
Trial lenses will be used to verify the contact lens selection. Lenses will be placed on your eye and 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.
You will be given instructions on how to care for your lenses and how long to wear them. You will also receive training on how to handle, apply and remove the lenses. Your follow up appointment will be set up within 1 – 2 weeks.
Regardless of how often or how long you wear your contact lenses, your eyes should be examined at least once a year.