The term Punctum Proximum refers to which optical landmark?

The term Punctum Proximum refers to which optical landmark?

• A. Far point
• B. Near point
• C. Retinal point
• D. Focal point

Answer: (B)

The idea being tested is the limit of accommodation—the closest distance at which the eye can form a sharp image when the ciliary muscle is fully contracted. This nearest point of clear vision is what the term punctum proximum refers to, i.e., the near point. When an object is moved toward the eye, the eye increases its refractive power to keep the image on the retina; at the near point, the image is just focused. If the object were brought any closer, the image would fall behind the retina and blur. The distance to this point also defines the amplitude of accommodation, which decreases with age (presbyopia). In contrast, the far point describes the farthest distance at which a clear image is formed with relaxed accommodation, and the other terms like retinal point or focal point don’t specifically denote this nearest-limit concept. So punctum proximum is the near point.

The idea being tested is the limit of accommodation—the closest distance at which the eye can form a sharp image when the ciliary muscle is fully contracted. This nearest point of clear vision is what the term punctum proximum refers to, i.e., the near point. When an object is moved toward the eye, the eye increases its refractive power to keep the image on the retina; at the near point, the image is just focused. If the object were brought any closer, the image would fall behind the retina and blur. The distance to this point also defines the amplitude of accommodation, which decreases with age (presbyopia). In contrast, the far point describes the farthest distance at which a clear image is formed with relaxed accommodation, and the other terms like retinal point or focal point don’t specifically denote this nearest-limit concept. So punctum proximum is the near point.