Human eye sees color by mixing the signal from three different cones cells in the retina. Cones sensitive to red, green and blue light respectively. The brain interpret color based on those three signals.
Elevated eye pressure is caused by a build-up of fluid (aqueous humor) inside the eye because the drainage channels (trabecular meshwork) cannot drain it properly. Elevated eye pressure can cause optic nerve damage and vision loss.
50 insane facts about the eye ( is amazing)! -From how much your eye weighs to what makes is in a tear drop, this insightful Infographic has you covered with everything you ever wanted to know about the human eye.