It is used to examine the retina and optic nerve.
It is part of the routine eye examination. It is done in two different ways.
It is done with a device called ophthalmoscope. The optic nerve, retinal vessels, macula, and other areas of the retina can be examined.
Especially in cases where the pupil is enlarged dilated (mydriasis), most of the retina can be examined.
It is an advanced form of examination and is performed with a special instrument called indirect ophthalmoscope.
Using high numbered lenses, the bottom of the eye can be seen with two eyes and a clearer image is obtained.