Slit Lamp Examination
How To Prepare continued...
Eyedrops may be used to widen (dilate) your pupils and to numb the surface of your eyes. Before the test, tell your doctor if you have glaucoma or are allergic to dilating or anesthetic eyedrops.
If dilating drops are used, your eyes may be sensitive to light and you will have trouble focusing your eyes for several hours. If you know your eyes will be dilated, you may wish to arrange for someone to drive you home after the test. You also will need to wear sunglasses when you go outside or into a brightly lit room.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).
How It Is Done
Most of the time, a slit lamp examination is done by an ophthalmologist or optometrist. In some situations, a family medicine doctor or an emergency medicine specialist may perform the test.
- The doctor may put one or more types of drops in your eye. Dilating drops may be used to make the opening (pupil) in the center of the eye bigger. This makes it easier for the doctor to see the structures of your eye. Anesthetic eyedrops may be used to numb your eye if a foreign body is to be removed or if eye pressure is being measured (tonometry). In some cases, fluorescein dye is used.
- You will sit in a chair and rest your chin and forehead against bars on the slit lamp. The lights in the room will be dimmed.
- The slit lamp will be placed in front of your eyes, in line with the doctor's eyes. Focus your eyes in the direction requested by the doctor and try to hold your eyes steady without blinking.
- A narrow beam of bright light from the slit lamp is directed into your eye while the doctor looks through the microscope. In some cases, a camera may be attached to the slit lamp to take photographs of different parts of the eye.