Contact lenses are placed directly on the surface of your eye to correct your vision.
They can correct short-sightedness (myopia) and long-sightedness (hyperopia). They can also correct astigmatism and age-related long-sightedness (presbyopia).
The principle of contact lenses is the same as for glasses. They bend light and redirect it towards your retina to give you improved eyesight.
What are contact lenses made of?
Nowadays most people wear soft contact lenses made of a moisture-rich material called hydrogel. Hydrogel lenses are breathable, so oxygen can pass through them to help keep your eyes healthy and feeling fresh.