For such a small organ, it has many important parts. From your lids and lashes to your Retina and Choroid, they all play a vital role.
Your lids and lashes are responsible spreading tears and for keeping things out of your eye. Hence your natural instinct to blink when something is coming towards your face. Your lid also houses your glands and tear ducts. Glands produce your tears, then tears gets funneled into your tear ducts. Then comes the Conjuctiva. Conjuctiva is a transparent sac that starts from the inside of your lids and goes over the whole eye. It's job is to keep the eye moist and protect it from infections. (Fun fact, it too had glands!)
The white part of your eye is called the Sclera. The Sclera is your Captain America shield. It's a tough part of your eye that provides structural integrity. That brings us to your Cornea. The Cornea is a clear dome that transmit light through your lens and allows it to refracts on the retina. Your Iris (colored part of the eye) controls the amount of light that enters the eye.
Now for the inside of the eye. Things just got exciting!
Vitrerous is the clear jellylike substance that occupies the dome. Its sole job is to keep the Retina (the light sensitive part) pushed against the Choroid for blood supply and nutrients. The Macula lies in the center of the Retina. Your Macula provides you with your sharp central vision. It also has the most cones concentration to provide you with color vision. The rest of the retina is lined with rods that detects movement and provide night vision. The Optic nerve is your WiFi. It takes all the information it gathers and sends it to your brain for interpretation.