Photosensitive

Photosensitive means that something is sensitive to light. Think about how your eyes react when you go from a dark room into a bright sunny day - your eyes need time to adjust to the brightness.

In the same way, certain materials or substances can react to different levels of light. For example, some types of paper or film used for photography are photosensitive. When light hits them, a chemical reaction happens that can capture the image that the light is shining on.

Some people also have conditions that make them photosensitive, which means that they are extra sensitive to light. This can cause them to have headaches or seizures when exposed to certain types of light.

Overall, being photosensitive just means that something or someone reacts to light in a particular way.