A visual guide to how we see, why vision changes and how light creates colour.

The Human Eye and the Colourful World: lesson notes

The human eye is a remarkable optical system. Light enters through the cornea, passes through the pupil and is focused by the eye lens onto the retina.

The retina converts this focused image into electrical signals. The optic nerve carries those signals to the brain, where they are interpreted as the world we see.

For board preparation, connect each defect of vision to the part of the focusing process that has changed. Myopia is corrected with a concave lens, while hypermetropia uses a convex lens.