Gonioscopy is a test for Glaucoma which measures the angle between the cornea (the outer transparent dome of the eye) and the iris (the coloured part of the eye). This angle is the drainage area from where the fluid drains out of the eye. Seeing if this angle is open or close gives an idea about the type and severity of glaucoma.
The eye doctor administers eye drops into your eyes to ensure that this test is absolutely painless. You would then be asked to sit facing a microscope and place your chin on a chin rest. The Gonioscopy lens is then gently placed onto your eye. You are required to stay stable as a narrow beam of light is directed on to your eye and your eye is examined through the slit lamp microscope. The entire test does not take more than 5 minutes to complete. You may experience blurry vision for a few hours after the test. Do avoid rubbing your eyes for about 20 minutes after the eye test. If you are a contact lens user, you would be advised to remove your lenses before the test and resume wearing them about an hour after the test or after the effect of the drops have worn off.
Gonioscopy is done to: