Spectral sensitivity

Imagine you have a special camera that takes pictures of colors. But instead of taking just one picture, it takes many pictures, each of a different color. This camera can take pictures of colors that are too bright or too dim for your eyes to see.

Now, imagine that you have a bunch of these cameras and each of them can take pictures of different colors. Some can take pictures of reds and oranges, others of greens and yellows, and others of blues and purples.

Spectral sensitivity is like having all of these special cameras but inside your eyes. Your eyes are sensitive to different colors of light, just like the cameras are. But instead of taking pictures, your eyes send signals to your brain telling it what colors they see.

Different animals and even different parts of your own eyes can have different spectral sensitivities. This means that some animals can see colors that you can't see, or they might see them differently. For example, some birds can see ultraviolet light, which is a type of light that is too blue for us to see.

So, spectral sensitivity is like tiny cameras in your eyes that let you see different colors, and different animals can have different colored cameras.