Slit Lamp Examination
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.
A test called fluorescein staining may be done along with
a slit lamp examination.
- During this test, your doctor applies a dye called
fluorescein as an eyedrop or as a paper strip that is gently touched to the
inside of your lower eyelid. The dye dissolves in your tears, coats your
cornea, and collects temporarily in any scratches or other abnormal areas. The
rest of the dye is washed away by your tears.
- Your doctor shines a light onto your eye. The fluorescein dye shows up under
the light, allowing the doctor to see scratches, ulcers, burns, or
areas of irritation from an infection or dryness.
A slit lamp examination takes about 5 to 10 minutes.
How It Feels
There normally is no discomfort involved
with a slit lamp examination.
Dilating drops may make your eyes
sting and cause a medicine taste in your mouth. You will have trouble
focusing your eyes for up to 12 hours after your eyes have been dilated. Your
distance vision usually is not affected as much as your near vision, though
your eyes may be very sensitive to light. Do not drive for several hours after
your eyes have been dilated. Wearing sunglasses may make you more comfortable
until the effect of the drops wears off.
Anesthetic drops usually
wear off in about 30 minutes.
In some people, the dilating or anesthetic
eyedrops can cause:
Contact your doctor immediately if you have severe and
sudden eye pain, vision problems (halos may appear around light), or loss of
vision after the examination.