The focused image is sensed by photoreceptors located at a nerve layer lining the inner surface of the back of the eye, called the retina. The function of retina is analogous to the film in a camera. The sensed images are converted into signals that are transmitted by the optic nerve to the brain.

The macula is the portion of the retina that is the most sensitive to light. It is responsible for straight ahead vision, fine details and colour perception. When retinal diseases had affected the macula, the vision in the eye will be significantly reduced.

The transparent vitreous gel occupies the space between the lens and the retina. With increasing age, the gel undergoes degeneration and separates from the retina. These changes and small irregularities in the gel’s consistency may cast a shadow on the retina, and can be perceived as ‘floaters’.

The retina gets its nutrients and oxygen from blood vessels within the retina layer itself and from the choroid.

Physical separation of the retina layer from the choroid (such as retinal detachment, or abnormal accumulation of fluid/blood between these layers as in age-related macular degeneration) leads to disruption in the function of the retina.

Our eye functions as a camera. In normal vision, (emmetropia) light rays enter the eye through the cornea and the image is focused on the back surface of the eye called the retina. The retina will then transmit the image of the object via the optic nerve to our brain to interpret.