Many people aren’t sure what to expect when they make an appointment with an eye doctor — especially if they’ve never had a comprehensive eye exam before or it’s been many years since their last exam.
Eye doctors use a wide variety of tests and procedures to examine your eyes. These tests range from simple ones, like having you read an eye chart, to complex tests, such as using a high-powered lens to visualize the tiny structures inside of your eyes.
A comprehensive eye exam can take an hour or more, depending on the doctor and the number and complexity of tests required to fully evaluate your vision and the health of your eyes.
While there are many ways for your eye doctor to check how your eyes work together, the cover test is the simplest and most common.
During a cover test, your eye doctor will ask you to focus on a small object across the room and will then cover each of your eyes alternately while you stare at the target. The test is then repeated with you looking at a near object.
During these tests, your eye doctor will assess whether the uncovered eye must move to pick up the fixation target, which could indicate strabismus or other problem that could cause eye strain or amblyopia (“lazy eye”).
Refraction is the test that your eye doctor uses to determine your exact eyeglass prescription.
During a refraction, the doctor puts the instrument called a phoropter in front of your eyes and shows you a series of lens choices. He or she will then ask you which of the two lenses in each choice looks clearer.
Based on your answers, your eye doctor will continue to fine-tune the lens power until reaching a final eyeglass prescription.
The refraction determines your level of hyperopia (farsightedness), myopia (nearsightedness), astigmatism and presbyopia.