How the eye works

If you are looking for a laser eye clinic in London, then the London Vision Clinic should be on your shortlist.  

That may seem like a strong statement, but the London Vision Clinic emphasises that, in expert hands, laser eye surgery can be an extremely safe, life enhancing experience. More than 100,000 laser eye surgery procedures will be done in the UK this year. Read the guide to Laser Eye Surgery to help make the right choice for your eyesight.

Contact London Vision Clinic

Your eye is like a camera. Your eye has:

•  A variable opening called the pupil;

• A lens system, which includes the transparent covering called

• the cornea and a spherical lens (LASIK eye surgery procedure

• is performed on the cornea);

• A reusable “film” called the retina;

• Various sets of muscles (the muscles control the size of the opening, the shape of the lens system

• and the movements of the eye).

On the back of your eye is a complex layer of cells known as the retina. The retina reacts to light and conveys that information to the brain. The brain, in turn, translates all that activity into an image. Because the eye is a sphere, the retina has a curved surface.

In the retina, sensory cells called rods and cones change the photons of light into electrical signals. Nerves transmit these signals to the brain, which interprets them.

The ability to focus the light on the retina depends on the shapes of the cornea and the lens. Inherent shapes, stretchiness or elasticity, the shape of the eyeball and sets of attached muscles influence the shapes of these anatomical components.

Therefore, when you look at something, muscles attached to the lens must contract and relax to change the shape of the lens system and keep the object focused on the retina, even when your eyes move.

Your nervous system controls this complex set of muscle movements.

When you look at something, three things must happen:

•  A reduction in the image to fit onto the retina;

• The scattered light must come together—that is, it must focus—at the surface of the retina;

• The curving of the image to match the curve of the retina.

The light passes through the cornea and pupil. The lens bends (refracted) the light, and it then comes to a point (focus) on the retina. As light enters the eye, it is focused on retina. To do this, the eye has a lens between the retina and the pupil (the “peep hole” in the centre of your eye that allows light into the back of the eye) and a transparent covering, or cornea (the front window). Thus the lens and the cornea work together to focus the image onto the retina.

Most vision problems occur when the eye cannot focus the image onto the retina. The most common problems are Myopia (short-sightedness), Astigmatism, Hyperopia (long-sightedness) and Presbyopia. In most cases, laser eye surgery corrects these vision problems.