The cornea is the glassy part of your eye that covers the whole front surface of the eye. The cornea includes the pupil, the anterior portion and the iris as parts of the eye. The main function of the cornea is to bend the light rays to provide us with better vision. It is also responsible for focusing these light rays.
The cornea is formed of cells and proteins and it doesn’t include very many blood vessels which is the opposite of most of the tissues of the human body. Sometimes, blood vessels might cloud the cornea and this makes it harder for the cornea to bend the light properly which may indirectly cause vision loss or problems. The blood vessels in the cornea are non-nutrient supplies, but the tears located in the anterior part provide nutrient supplies for cornea.