Final answer:
Improvement in vision through a pinhole suggests astigmatism because it reduces the blur from irregular light refraction due to the eye's shape. Myopia and hyperopia relate to the eyeball's length and lens power, while presbyopia originates from lens hardening with age.
Step-by-step explanation:
If a patient's vision improves by reading through a pinhole, this suggests option 1: Astigmatism. When a person has astigmatism, their eye has an irregular shape causing light to be refracted incorrectly, which leads to blurry vision. The pinhole works by eliminating the peripheral light rays and allowing only the central rays to enter the eye, which lessens the blur caused by astigmatism and sharpens the vision. Options 2: Myopia (nearsightedness) and option 4: Hyperopia (farsightedness) may benefit from pinhole testing, but not as markedly as astigmatism, since these conditions are related to the length of the eyeball and the focusing power of the lens. Option 3: Presbyopia typically begins to affect individuals in their mid-40s and is caused by the hardening of the lens of the eye, which affects the ability to focus on close objects.