Ophthalmoscopy is an examination of the back part of the eye (fundus), which includes the retina, optic disc, choroid, and blood vessels.
How the Test is Performed
There are different types of ophthalmoscopy.
Direct ophthalmoscopy: You will be seated in a darkened room. The health care provider performs this exam by shining a beam of light through the pupil using an instrument called an ophthalmoscope. An ophthalmoscope is about the size of a flashlight. It has a light and different tiny lenses that allow the provider to view the back of the eyeball.
Indirect ophthalmoscopy: You will either lie or sit in a semi-reclined position. The provider holds your eye open while shining a very bright light into the eye using an instrument worn on the head. (The instrument looks like a miner's light.) The provider views the back of the eye through a lens held close to your eye. Some pressure may be applied to the eye using a small, blunt probe. You will be asked to look in various directions.
Slit-lamp ophthalmoscopy: You will sit in a chair with the instrument placed in front of you. You will be asked to rest your chin and forehead on a support to keep your head steady. The provider will use the microscope part of the slit lamp and a tiny lens placed close to the front of the eye. The provider can see about the same with this technique as with indirect ophthalmoscopy, but with higher magnification.
The ophthalmoscopy examination takes about 5 to 10 minutes.
How to Prepare for the Test
Indirect ophthalmoscopy and slit-lamp ophthalmoscopy are performed after eyedrops are placed to widen (dilate) the pupils. Direct ophthalmoscopy and slit-lamp ophthalmoscopy can be performed with or without the pupil dilated.
The eyedrops may make it hard for you to focus your eyes for several hours. You should arrange to have someone drive you after the examination. Wearing sunglasses or tinted lenses will help your eyes feel more comfortable.
Separation of the light-sensitive membrane (retina) in the back of the eye from its supporting (retinal tear or detachment)
Ophthalmoscopy is considered to be 90 to 95% accurate. It can detect the early stages and effects of many serious diseases. For conditions that cannot be detected by ophthalmoscopy, there are other techniques and devices that may be helpful.
The test itself involves no risk. In rare cases, the dilating eyedrops cause:
An attack of narrow-angle glaucoma
Dryness of the mouth
If narrow-angle glaucoma is suspected, drops are usually not used.
American Academy of Ophthalmology Preferred Practice Patterns Committee. Preferred Practice Pattern Guidelines. Comprehensive Adult Medical Eye Evaluation -- 2010. Available at: one.aao.org/preferred-practice-pattern/comprehensive-adult-medical-eye-evaluation--octobe. Accessed February 26, 2015.
Colenbrander A. Principles of ophthalmoscopy. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 2013 ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:vol 1, chap 63.
Volk D. Aspheric lenses. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 2013 ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:vol 1, chap 50.
Franklin W. Lusby, MD, ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.