The eye is like a camera with a lens in front and a film (retina) at the back. The retina is located approximately two centimeters behind your pupil. It is shaped like a small cup. The retina converts the ocular image into a signal that is sent to the brain. The central part of the retina, called the macula, is used for straight-ahead vision and what is in your direct line of sight.
A healthy macula is crucial for tasks involving fine vision such as reading, recognizing faces and distinguishing things. The area surrounding the macula helps in mobility and in seeing from the ‘corner’ of the eye, though it is not useful for fine work. The retina is connected to the brain by the optic nerve. Blood is supplied to the retina and the optic nerve by blood vessels that maintain the health of these tissues. In front of the retina is the vitreous cavity, which is filled with a gel-like substance, called the vitreous.
Diseases of the retina, the vitreous, and the optic nerve can cause serious vision problems. Fortunately, most of them can now be managed satisfactorily with modern methods of diagnosis and treatment.