What is Pre-Testing?
Before you see an Optometrist, a variety of test may be done to gather basic information about your vision and visual needs. Such test include eye health history, check in forms, neutralizing your current pair of eyeglasses, auto-refraction, aberrometry, and non-contact tonometry. An optometric assistant or technician will help gather this information before you see the Optometrist so that they have a base line of your eye health in your file. With this information, the Optometrist can better address your concerns and eye care needs.
Autorefractors and aberrometers
Your eye doctor also may use an autorefractor or aberrometer to automatically estimate your eyeglass prescription. With both devices, a chin rest stabilizes your head while you look into the instrument at a pinpoint of light or a detailed image.
An autorefractor, like a manual refraction, determines the lens power required to accurately focus light on your retina. Autorefractors are especially helpful for determining an eyeglass prescription for young children and other patients who may have trouble sitting still, paying attention and providing feedback that the eye doctor needs to perform an accurate manual refraction. Studies have shown that modern autorefractors are very accurate. They also save time. The autorefraction takes only a few seconds, and the results greatly reduce the time required for your eye doctor to perform a manual refraction and determine your eyeglass prescription.
An aberrometer uses advanced wavefront technology to detect even obscure vision errors based on the way light travels through your eye. Aberrometers primarily are used for custom or wavefront LASIK vision correction procedures, but many eye doctors are now incorporating this advanced technology into their routine eye exams as well.
This test helps diagnose glaucoma. The Optometrist will use a tool called a tonometer machine or hand held that blows a tiny puff of air or gently touches your eye, measuring eye pressure indirectly by the eye’s resistance to the puff or sterilized instrument. Applanation instruments can also measure pressure. They are the most accurate, but local anesthetic is required. An optometric assistant or technician will also use a machine to help measure eye pressure. This machine also blows a tiny puff of air, but allows you to comfortably rest your chin and forehead while the test is being administered. Newer technology allows a more comfortable eye pressure testing experience. Usually patients will feel surprised or shocked, but with the advanced technology makes it quick and easy. Visit your eye care professional to learn more.