How to see the fundus or retina of an eye

 Retina is the inner most layer of the eye ball that is responsible for sensing light. We can not see the retina with naked eye because our cornea and lens  make the light coming from the retina parallel and hence the image formed at infinity. So in order to see the retina we have to over come the power of cornea as well as natural lens. 

There are many methods to examine the retina but the most handy and useful method is distant direct ophthalmoscopy. This method is performed by an instrument called Ophthalmoscope or fundoscope. This instrument uses built-in light source and magnifying lenses. It magnifies 15times the original size of fundus. 

In order to see the retina we have to sit the patient in a comfortable posture and hold the ophthalmoscope in the right hand in order to examine the right eye of the patient at the level of the patient . Approach the pupil of the eye of patient 15-30' lateral to the axis of the eye. Optic disc will come into focus at the distance of 3.5cm from the eye.

If the disc is not focused then a built-in series of lenses mounted on a dial is rotated until disc is focused. Then arterial arcades emerging from the disc are observed and noted. In this way whole of the retina is seen.

For examining the left eye of the patient left eye and left hand of the examiner is used and the patient's eye is temporally approached to observe the optic disc into focus. In order to reduce the reflection from the cornea, polar filters are present in the ophthalmoscope.