The retina is the thin, light-sensitive layer at the back of your eye — about as thick as a sheet of paper, but extraordinary in what it does. Every time you read, recognise a face, drive, or look at your phone, your retina is converting light into electrical signals that travel through the optic nerve to your brain. Most diseases that cause permanent loss of central vision involve the retina, which is why understanding it matters.

What the Retina Does

The retina has two main jobs:

• It captures light. Millions of tiny photoreceptor cells called rods and cones sit in the retina. Cones give us sharp daylight vision and colour; rods give us night and peripheral vision.
• It sends signals to the brain. The photoreceptors pass signals through several layers of nerve cells, which then leave the eye together through the optic nerve.

The Macula and the Fovea

The macula is a small, specialised area at the centre of the retina, about 5–6 mm across. It is packed densely with cones, and is responsible for everything you do with sharp central vision — reading, recognising faces, threading a needle, seeing fine print.

At the very centre of the macula is an even smaller pit called the fovea. The fovea is your eye’s “high-definition zone”. Damage to the fovea, even by a fraction of a millimetre, can dramatically reduce sight, while the rest of the eye looks perfectly normal. This is why most retinal diseases that affect vision do so by damaging the macula.

The Blood Supply of the Retina

The retina has two blood supplies. The inner half is fed by the retinal arteries branching out from the optic nerve. The outer half (including the photoreceptors) is fed indirectly by a rich layer of vessels behind the retina called the choroid. When either supply is disturbed — by diabetes, high blood pressure, blockage of a vessel, or age-related disease — the retina suffers and vision drops.

Why the Retina Matters in So Many Diseases

Unlike many other tissues in the body, retinal cells do not regenerate. Once damaged, they are usually lost for good. That is why every retinal disease we treat shares the same principle: catch it early, treat it early, protect what is still healthy. Most blindness from retinal disease is preventable when the disease is recognised in time.

How We See the Retina at Suraj Eye Institute

The retina is one of the only places in the body where a doctor can look directly at living blood vessels and nerve tissue, without an operation or scan. We use:

• Dilated fundus examination — an eye doctor looks inside your eye after dilating the pupil with drops.
• Fundus photography — a high-resolution colour photograph of your retina.
• OCT (Optical Coherence Tomography) — a non-contact scan that shows the layers of the retina in cross-section.
• OCT-Angiography — a dye-free scan of the retinal circulation.
• Fluorescein and ICG angiography — dye-based scans for leakage and choroidal disease.