WhatYouNeedToKnowAboutAnEyeExam
Five Tests Done During The Exam
Visual Acuity Test
This test measures how clearly you see. Your doctor will ask you to identify different letters of the alphabet printed on a chart (Snellen chart) positioned a little away from you. The lines of type get smaller as you move down the chart.
Eye Muscle Test
This test examines the muscles that control eye movement, looking for weakness, poor control or poor coordination. Your eye doctor watches your eye movements as you follow a moving object, such as a pen or light, with your eyes.
Visual Field Test
The visual field test determine whether or not you have difficulty seeing in any spots of your vision. There are three different types of tests:
- Confrontation Visual Field Exam. Your eye doctor sits directly in front of you and asks you to cover one eye. You look directly at your eye doctor while he or she moves his or her hand in and out of your visual field. You tell your doctor when you can see his or her hand or fingers and how many fingers you see.
- Tangent Screen Exam. You sit a short distance from a screen and focus on a target at its center. You tell your doctor when you can see an object move into your peripheral vision and when it disappears.
- Automated Perimetry. Your eye doctor or a technician uses a computer program that flashes small lights as you look into a special instrument. You press a button when you see the lights.
Color Vision Testing
Your doctor shows you several multicolored dot-pattern tests. If you have no color deficiency, you'll be able to pick out numbers and shapes from within the dot patterns. However, if you do have a color deficiency, you'll find it difficult to see certain patterns within the dots. Your doctor may use other tests, as well.
Retinal Examination
Allows your doctor to evaluate the back of your eye, including your retina, optic disk and the underlying layer of blood vessels that nourish the retina. Usually before your doctor can see these structures, your pupils must be dilated with eyedrops that keep the pupil from getting smaller when your doctor shines light into the eye.
- Direct examination. Your eye doctor uses an ophthalmoscope to shine a beam of light through your pupil and to see the back of your eye. Sometimes eyedrops aren't necessary to dilate your eyes before this exam.
- Indirect Examination. During this exam, you might lie down, recline in a chair or sit up. Your eye doctor examines the inside of the eye with the aid of a condensing lens and a bright light mounted on his or her forehead. This exam lets your eye doctor see the retina and other structures inside your eye in great detail and in three dimensions.
- Slit-lamp exam. In this exam your doctor shines the beam of a slit lamp through a special lens into your eyes. The slit lamp reveals a more-detailed view of the back of your eye.