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
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
optometrist. In some situations, a
family medicine doctor or an
emergency medicine specialist may perform the
- 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
- 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.