OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

How can short-sightedness be corrected?

1. Using thick glasses with convex lenses

2. Through behavioral therapy

3. Using concave lenses in glasses or contact lenses

4. Watching television in better lighting

The correct answer is: Using concave lenses in glasses or contact lenses

Short-sightedness, or myopia, occurs when the eye focuses images in front of the retina instead of directly on it, leading to blurred vision for distant objects. The correction for this condition involves adjusting the light entering the eye so that images are properly focused onto the retina. Concave lenses, which are thinner at the center and thicker at the edges, are used to diverge light rays before they enter the eye. This divergence allows the light rays to focus further back, directly on the retina, enabling clearer vision for distant objects. The use of these lenses in glasses or contact lenses effectively compensates for the eye's shape or refractive error that is characteristic of short-sightedness. In contrast, options like using thick glasses with convex lenses would actually worsen myopia, as convex lenses are used for far-sightedness where light needs to be converged. Behavioral therapy and watching television in better lighting do not address the refractive error of the eye; they may improve comfort or habits but do not correct the underlying problem of image focus.