Adults should have a comprehensive eye exam every one to two years, and the exam includes a variety of tests to assess the health and visual quality of a person’s eyes. The tests range from simple to complex, from reading a chart of letters to having your eyes examined with a high-powered lenses. Here are 7 tests you can expect to go through as your have your eyes examined: ‍

1. Retinoscopy

This test is used to determine the prescription you will need for eyeglasses. For this test the lights in the room are dimmed, and a device (the phoropter) containing wheels of lenses is positioned in front of your face. You will be directed to focus on letters across the room, as your eye doctor doctor shines a light into your eyes and changes the different lenses in the device. The doctor analyzes how the light reflects in your eyes and can determine the best prescription for your eyes. Retinoscopes are most useful for children or patients who can not communicate and accurately answer the eye doctor’s questions. ‍

2. Refraction

The doctor uses Refraction testing to evaluate your exact prescriptions for eyeglasses. For this test the doctor puts the phoropter in front of your eyes and shows you a series of different lenses. The doctor will then ask you to compare two lenses, and ask you which one gives you better vision. The answers you give will determine how much farsightedness, nearsightedness, or astigmatism you have, and also which eyeglass lenses you need to correct these problems. ‍

3. Aberrometers and Autorefractors

Both tests are used to help determine your prescription for eyeglasses. When undergoing these tests, the doctor has you rest your chin on the device, and instructs you to look at a pinpoint of light or image to examine your eyes. The aberrometer uses complex wavefront technology to identify errors in your vision based on the way the light travels in your eye. An Autorefractor examines how your retina focuses on images, which is where vision processing occurs. ‍

4. Cover Test

The Cover test is used to determine how your eyes work together. During this test, the eye doctor will ask you to focus on a small object that is located a far distance away, then will cover one of your eyes as you continue to stare at the object. The doctor analyzes how far the eye has to move to refocus on the object after one eye is covered. The cover test is then repeated to analyze how your focus changes on an object that is closer. ‍

5. Slit-Lamp Examination

The slit-lamp highly magnifies your eyes to enable your doctor to get a closer look at your eyes. For this test you will place your chin on a chin rest, and look into an illuminated microscope. After looking at the front surface of your eye, the doctor will use hand-held devices to further examine your retina. ‍

6. Tonometry (Testing for Glaucoma)

Tonometry is the name for a variety of tests that ultimately examines the pressure in your eyes. High levels of eye pressure can lead to glaucoma, which is vision loss caused damage to the optic nerve. The air puff test is conducted by using a small device to release a small burst of air into your eye. The doctor then examines your eye’s resistance to the puff of air. Another common way to test for Glaucoma is with a device called an applanation tonometer. For this test the doctor places yellow eye drops inside of your eye. These eye drops make your eyes feel slightly heavy, and cause your eyes to go numb. Next the doctor places a blue glowing probe onto the front surface of each eye, and measures your eye pressure. Both tests are painless and take only a few seconds. ‍

7. Pupil Dilation

Some comprehensive exams require having your eyes dilated. Eye drops are used to cause the dilation, and after 20 minutes your pupil will be enlarged. Widening your pupil allows for your doctor to get a better view of the internal structures of your eye. After your eyes are dilated, you will be very sensitive to light, and for the next few hours you will have difficulty reading or focusing on close objects. ‍