What is the term for the condition where parallel rays of light focus behind the retina?

The condition where parallel rays of light focus behind the retina is known as hyperopia, or farsightedness. In hyperopia, the eye is either too short from front to back or is unable to focus light correctly, causing distant objects to be perceived more clearly than those that are nearby. This results in the focal point being positioned behind the retina, which is why individuals with hyperopia may struggle to see close-up objects clearly.

Astigmatism involves an irregular curvature of the cornea or lens that results in distorted or blurred vision for both near and distant objects. Myopia, or nearsightedness, is the opposite condition where the focal point falls in front of the retina, making nearby objects appear clear while those at a distance are blurry. Diplopia refers to double vision, which is a symptom rather than a refractive error and can occur for various reasons, including eye muscle imbalances. Understanding these distinctions helps clarify why hyperopia is the correct term for the condition described in the question.