The Retina: What Does the Retina Do?

What the Retina Is and How It Makes Vision Possible

Diagram of the eye, depicting the "rods and cones" of the retina
Diagram of the eye, depicting the "rods and cones" of the retina. Getty Images/BSIP/UIG

Definition: The retina is located on the inside of the eye. It is the light-sensitive area located at the back of the eye that the lens focuses images upon.

How the Retina Works

The retina is made up of ten extremely thin layers that are very light sensitive.   Within these layers are the rods and cones detect color versus black and white. The lens of the eye focuses images on the retina, and in turn, the retina processes those images.

 The retina takes in the focused images, turns them into electrical impulses, which are then sent to the brain for interpretation.

​The retina is fragile. A detached retina happens when the retina attempts to separate from the other structures of the eye, and typically happens during contact sports or because of trauma. Boxing in particular is known to cause retinal detachments. 

The Appearance of the Retina

In normal day to day life you cannot see the retina, with one major exception: photos taken with a flash.  The red eye effect that happens in photos is caused by the retina, which normally appears red when examined by a healthcare professional with a light, or when it is photographed. This is due to the large quantity of blood that flows through the retina.

An absence of this redness, or changes in it, can indicate a problem with the eye. Some people have been diagnosed with eye problems by the appearance of their eyes in photos: one eye appeared red and the other did not.

 The blood vessels that run through the retina have another interesting feature:  they are so unique that they can be used for identification, much like fingerprints, using a retinal scan. No two humans have the same pattern of blood vessels in their eyes.

Examination of the Retina

A retina can be examined by a healthcare professional using an ophthalmoscope, a device with a light that allows the retina to be seen.

You have probably experienced this type of examination during a standard checkup.

The best way to look at the anatomy of the retina is with a digital retinal imaging scan, which produces a full color image of the retina for better examination. 

Also Known As: retina, retinal,

Common Misspellings: retinuh, retinah, retena,

Examples: The boxer sought treatment when he was diagnosed with a detached retina.

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