You are asked to research what the eye is. You read that it contains nerves, muscles, and blood cells. Therefore, you decide that it is what?

The eye is an organ.

Explanation:

Organs are structures made up from different tissues, such as nervous tissue, muscle tissue, epithelial tissue and blood tissue (a type of connective tissue). These tissues, with their own specialized cells, work organizedly to make the organ function as it's supposed to do.