Red-eye has ruined more good shots than probably any other quirk produced by light when taking a photo. It is caused by light from a flash hitting the eyes and the light is reflected back into the lens.

Red-eye is particularly problematic when using a tiny built-in digital camera flash because of it’s proximity to the lens.

Digital cameras have a red-eye flash mode that fires a series of pre-flashes prior to the final flash. The rapid flashes cause pupils to contract and may help reduce the reflection.

Though not perfect, red-eye flash mode can help minimize the red-eye effect. When using this mode, inform your subjects since the pre-flashes may startle them and cause weird expressions on their faces.

Look towards to camera, not the flash

When using a built-in flash, have the subject look toward the camera but not directly at the lens. Don’t rely solely on the flash for illumination. Use other sources to illuminate a room such as light coming through a window or door. If you must turn on additional room lights, make sure to adjust the white balance setting.

Some digital cameras remove red-eye in the camera. However it is not always as effective so you’ll have to use an image editing program to remove it.

The most effective way to prevent red-eye is to use an external flash.