Ophthalmoscopy is performed with an ophthalmoscope and allows the ophthalmologist to examine the retina and vitreous. Opthalmoscopy is usually performed with dilated pupils, to allow the best view inside the eye.
Two types of ophthalmoscopes may be used: direct and indirect. The direct ophthalmoscope has a battery powered light source and is hand-held. Multiple lenses may be selected with a dial, which allows the doctor to focus on and view the optic nerve and the central retina.
The periphery, or entire retina, may be viewed by using an indirect ophthalmoscope, which is worn on the doctor's head. A lens is placed in front of the patient's eye while the doctor looks through the magnifying glasses in the headgear. The combination of the instrument and the lens allows a good view of the entire retina.