How Is Astigmatism Diagnosed?
The diagnosis of astigmatism is based on an eye exam. There are a variety of tests to examine the health of the eyes, as well as a refraction, which determines how the eyes bend light. As your eye doctor examines you, he or she may use various instruments and point bright lights directly at your eyes. These tests help your optometrist or doctor determine whether you need eyeglasses or contact lenses to provide clear vision and to examine different aspects of your vision and eyes. Your doctor can achieve precise results with a variety of tests and devices. These may include; (4)
Visual Acuity Assessment
For your optometrist to assess your clarity of vision at different distances, you will be asked to read from a distance chart.
Refraction Test
Refraction tests involve the doctor placing various lenses before your eye, then using light to measure how it bends through the cornea. An optometrist may then use a phoropter to measure the focusing power of your eyes in order to determine which lens will provide the best vision.
Keratometry
Your optometrist uses keratometry to measure the curvature of your cornea. In this test, a circle of light is focused on your eyes’ curve and its reflection is measured. This machine measures the bend in your cornea’s center and finds the steepest and flattest curves. Your doctor can find out your cornea’s shape and how well it can focus from the measurements.
Auto refractor
Light is projected into your eye and measured as it bounces off the back. Your doctor can then determine the type of lens you need.
Corneal Topography
Astigmatism is increasingly being diagnosed using corneal topography. These measurements provide a comprehensive picture of the shape of the cornea. An optometrist can use this computer-assisted diagnostic tool to create a contoured map of the cornea and determine its exact shape.
You are instructed to look at a specific point by your doctor. At the same time, the device takes thousands of measurements. The data is processed by a computer to create a color map of your cornea. In case your doctor plans to operate due to astigmatism or cataracts, he or she will consult this guide. It may be used to fit contact lenses. Keratoconus may be diagnosed with it.