Defects of the eyeSpec 4.5.2.3
In short
Myopia (short sightedness) and hyperopia (long sightedness) are defects of the eye in which light rays do not focus on the retina. In myopia rays focus in front of the retina and a concave lens corrects it. In hyperopia they focus behind the retina and a convex lens corrects it. Contact lenses, laser surgery and replacement lenses are newer treatments.
Two common defects of the eye are myopia (short sightedness) and hyperopia (long sightedness). In both, rays of light do not focus on the retina.
| Myopia (short sightedness) | Hyperopia (long sightedness) | |
|---|---|---|
| Effect | Distant objects look blurred | Near objects look blurred |
| Where light rays focus | In front of the retina | Behind the retina |
| Correction with spectacle lenses | Concave lens, which spreads the light rays slightly before they enter the eye | Convex lens, which bends the light rays inwards before they enter the eye |
(opens full size in a new tab)Generally these defects are treated with spectacle lenses which refract the light rays so that they do focus on the retina. New technologies now include:
- hard and soft contact lenses
- laser surgery to change the shape of the cornea
- a replacement lens in the eye.
In a ray diagram question, say where the rays meet (in front of, behind or on the retina) and which lens moves that point onto the retina.
Written and checked against the AQA GCSE Biology (8461) specification · Updated October 2026