AQA new specification-Common problems of the eye-B10.6

Common problems of the eye lesson created in accordance to the NEW AQA Specification (9-1). Designed for a higher ability, separate science class, although content can be adjusted to suit any ability. Includes powerpoint timers, slide animations, embedded video’s, homework worksheet, markscheme and mini review. NB: If you are unable to play embedded videos please view slide notes for link.

THIS LESSON IS FOR BIOLOGY ONLY

AQA spec link: 4.5.2.3
Relevant chapter: B10 The human nervous system. AQA Biology Third edition textbook-Page 156-157
Students are required to know the following;
Students should be able to relate the structures of the eye to their functions. This includes: • accommodation to focus on near or distant objects

Accommodation is the process of changing the shape of the lens to focus on near or distant objects.
To focus on a near object:
• the ciliary muscles contract
• the suspensory ligaments loosen
• the lens is then thicker and refracts light rays strongly.

To focus on a distant object:
• the ciliary muscles relax
• the suspensory ligaments are pulled tight
• the lens is then pulled thin and only slightly refracts light rays.

Two common defects of the eyes are myopia (short sightedness) and hyperopia (long sightedness) in which rays of light do not focus on the retina.
• 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, and a replacement lens in the eye.
Students should be able to interpret ray diagrams, showing these two common defects of the eye and demonstrate how spectacle lenses correct them.