Measurement of the eye’s surface and curvature: An instrument called a keratometer will be used to measure the curvature of your eye’s clear front surface (cornea). It automatically assesses images of your cornea and creates mathematical representations of the curvature of the eye’s surface (K-readings). These measurements help the optometric physician determine the proper curve and size of the contact lenses. Corneal Topography may also be used. It provides precise details about surface characteristics of the cornea by analyzing photographic images taken of the way light projected into your eye travels. A computer creates and prints a surface “map” of the eye, with different contours represented by different colors.
Pupil and Iris measurements: These are taken with a pupil card, ruler or pupillometer to determine the eye’s pupil and iris size. This is done to help achieve a proper sizing and orientation of the contact lenses.
Tear film evaluation: The eye’s moisture content is evaluated through use of a small strip of paper inserted underneath the lower eyelid.
Evaluation of the eye’s surface and contact lens fit: The health of the cornea is evaluated using a biomicroscope. This lighted instrument with magnification will provide detailed information about the eye’s surface as a baseline for the optometric physician to evaluate any future changes to the eyes, related to contact lens wear. The biomicroscope is also used to evaluate the fit of trial contact lenses.
After finding a contact lens that fits properly, is comfortable and provides the best vision, the optometric physician will write a prescription. This prescription will designate contact lens power, a shape matching the curvature of the eye (base curve) and diameter.
It typically takes at least two office visits to complete the contact lens fitting. After that, your eyes will need to be examined annually so the physician can monitor the health of your eyes.