What Causes Red Eyes in Photos?

by David Em

Portraits Refined may earn a commission on purchases made from links on this page. For more information, read Affiliate Disclosure.

Have you taken a photo with a flash and noticed that your subject’s eyes are red? Learn why red eyes happen and how to fix it.

Photographer looking into the viewfinder of a Nikon camera with off-camera flash.

What causes red eyes in pictures?

The red-eye effect in photography is normally caused by the camera flash or a bright light source that’s reflected from the retina.

Related: Ultimate guide to lens flare

Since the camera flash is fast, the pupils don’t have time to contract and control the amount of light traveling into the eye.

The red comes from light reflecting off of the red blood vessels of the choroid, which is a layer of tissue in the back of the eye (Source: Yale Scientific).

How to prevent it

The best way to prevent the red-eye effect is to not use flash, which can be difficult in low-light situations.

Related: Best low-light lenses for portraits

However, it may be possible to find other ways to illuminate your subject, such as using light stands or finding locations with sufficient light.

If you need to use flash, make sure your camera has the red-eye reduction feature. Most modern cameras have this feature, which emits a brief succession of light to prepare your subject’s eyes.

Related: 5 tips for powerful close-up portraits

Additionally, you can have the subject look slightly away from the camera to avoid looking directly into the lens.

When it comes to flash photography, the red-eye effect is common. There are many ways to avoid it. If you need to correct the color, you can do so in post-processing.

Featured image courtesy of Unsplash.

About Portraits Refined

Portraits Refined (PR) is a media company that publishes the latest expert-backed portrait photography tips, in-depth camera gear reviews, and advice to grow your photography business. Learn more about Portraits Refined