GCSE; Edexcel; Coordination and control - The nervous system - Edexcel Common defects of the eye and how they can be overcome. The nervous system enables humans to react to their surroundings and ...

Two common defects of the eyes are myopia (short-sightedness) and hyperopia (long-sightedness). In both cases, rays of light do not focus on the retina so a clear image is not formed. These two ...