Answer :
Final answer:
The correct answer is D. The poorest vision score is 20/100, indicating that what is visible at a distance of 100 feet to a person with normal vision, the patient can only see from 20 feet.
Explanation:
The score that indicates the patient with the poorest vision among the options provided is D. 20/100. The first number in a vision score represents the distance at which a person can see a certain object, and the second number represents the distance at which a person with normal vision can see the same object. A score of 20/100 means that what the average person can see at 100 feet away, the person with the 20/100 vision must be as close as 20 feet to see.
For instance, consider someone with a score of 200/20. This would mean that they would have to be at 200 feet to see what a person with normal vision can see at 20 feet, which might seem poor, but it's important to remember that larger numbers in the numerator indicate worse vision. However, the higher number in the denominator for score D (20/100) implies that such an individual has worse vision because they can see at 20 feet what a person with normal vision can see at 100 feet.
Scores such as 18/20 and 24/20 actually indicate better than or essentially normal vision, respectively, since they can see at 20 feet what a normal-vision person sees at 18 or 24 feet away. In contrast, the score of 20/100 represents a significant visual impairment, since the person must be much closer to the object than a normal-sighted person to see it clearly.
When correcting vision, lenses with a certain diopter measurement are used to compensate for the refractive error. A diopter (D) is the unit of measurement for the refractive power of a lens. Myopia, or nearsightedness, requires negative diopter lenses to correct the focus. For example, a lens with a power of -5.00 D would be needed to correct a very myopic person's vision who has a far point of 20.0 cm to normal.
