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

What physical characteristic can cause someone to be long sighted?

1. Too short of an eyeball

2. A lens that bends light too much

3. An irregular cornea shape

4. Excessive pupil size

The correct answer is: Too short of an eyeball

Long sightedness, or hyperopia, occurs when the eye is unable to focus on nearby objects. This condition typically arises when the eyeball is too short relative to the focusing power of the cornea and lens. As a result, light entering the eye is focused behind the retina, making close objects appear blurry. The other factors listed are less relevant in causing long sightedness. For instance, a lens that bends light too much would lead to short sightedness, where images are focused in front of the retina. An irregular cornea shape can lead to astigmatism, a different refractive error, while excessive pupil size does not significantly impact the ability to see nearby objects clearly. Thus, the correct choice illustrates how the physical characteristic of an eyeball that is too short can lead to long sightedness.