What is a Slit Lamp Used for During Eye Exams?

Patient at slit lamp of optician or optometrist

A slit lamp exam is part of a comprehensive eye examination.

This…beautiful instrument utilised the principle of the fluorescence of living transparent tissues in a focused beam of light…it was like cutting a microscopic section through live tissue and many things undreamt of were revealed.” -Ophthalmologist Dame Ida Mann circa 1920’s

Slit-Lamp Biomicroscopy

A slit-lamp biomicroscope is a diagnostic instrument used by eye care professionals. The slit lamp exam, also called biomicroscopy, is performed by either an ophthalmologist or Doctor of Optometry during a routine vision check.

Parts of a Slit Lamp

  1. Slit lamp – illumination system
  2. Illumination arm – where the light gets mounted to on the machine
  3. Biomicroscope – binocular microscope
  4. Viewing arm – holds the microscope in place
  5. Patient positioning frame – includes the chin rest and forehead strap
  6. Joy stick – to adjust the position of the microscope and slit lamp
  7. Power switch – to turn the machine on and off

What is a Slit Lamp Used for During Eye Exam?

slit lamp biomicroscopy

Eye doctors use a slit lamp biomicroscopy during annual eye exams.

When’s the last time you had your eyes examined? Have you ever wondered what all those different machines and devices used by the eye doctor really do? A slit lamp is one of the many instruments used to test your vision during a comprehensive eye examination.

Besides being used to determine your eyeglass prescription, the machine also aids in the correct fitting of contact lenses. The doctor looks at both the interior and exterior structures of your eyes during this test including your eyelids and eyelashes.

A slit lamp uses a narrow band of light to give a magnified 3D view of the eyes during an eye exam. The eye doctor uses the instrument to examine the various structures in your eyes including the cornea, lens, iris and sclera. This piece of equipment diagnoses many diseases of the eye including uveitis, macular degeneration and cataracts.

Dilated Eye Exam

If you wear contacts or eyeglasses you will need to remove them. The optometrist will have you place your head in the patient position frame so your chin and forehead rest on it. A fluorescein dye is often placed into your eye before the biomicroscopy exam begins to allow the doctor to detect scratches, burns or ulcers on your eyes.

The doctor might also place drops in your eyes to dilate your pupils so he can get a better look inside your eyes. This is called a dilated eye exam. If dilating eye drops are used, your eyes will be sensitive to light for a few hours. You should arrange for a friend or family member to drive you to and from your exam and you may want to wear a pair of sunglasses after the exam is complete.

Schedule Your Next Eye Exam

Call Stanton Optical at 877-518-5788 to schedule your annual eye exam with a licensed Doctor of Optometry. Our eye care professionals, who are independent doctors of optometry or work for T. Campen, will do many tests during your appointment including glaucoma screening, color vision deficiency and a slit-lamp examination.

Most eye doctors recommend yearly vision checks to make sure your prescription hasn’t changed. At the very least you need to have your eyes checked every 2 years if you wear glasses and every year if you wear contacts lenses.

Slit Lamp Resources