Question

A camera flash can create what in a photograph of a person?

Answer 1

Red eyes

Explanation:

When you use flash on a person with their eyes open their eyes will come back as red, another example is a dog, when you turn of flash for the dog their eyes come back red, so the answer is red eyes.

Answer 2

This isn't really mathematics but I can give you an answer.

Assuming, it's in the dark (cuz in the light, why would you use flash), a person in the photograph can gain a red-eye (in the photo).

The only one I can think of is red eye.