American Board of Opticianry (ABO) Practice Test

What could a prescription of +1.50 OU indicate in optometry?

1. A. Myopia in both eyes

2. B. Hyperopia in both eyes

3. C. Astigmatism in both eyes

4. D. Presbyopia in both eyes

The correct answer is: B. Hyperopia in both eyes

A prescription of +1.50 OU (which stands for "oculus uterque," meaning both eyes) indicates hyperopia, or farsightedness, in both eyes. This condition occurs when the eye does not refract light properly, leading to difficulty focusing on nearby objects while distant vision may still be clear. The positive sign before the prescription value (+1.50) confirms this diagnosis, as hyperopia is represented by positive lens values. The strength of the prescription (+1.50) suggests a mild to moderate degree of hyperopia, meaning that the person requires corrective lenses that have a convex shape to help focus light correctly on their retina. Convex lenses are thicker in the middle and thinner at the edges, which helps to converge light rays that enter the eye, improving the focal point for vision at closer distances. Understanding why other options are incorrect further clarifies the nature of the prescription. Myopia (nearsightedness) would be denoted by a negative value, astigmatism would involve cylindrical notation (indicating a combination of spherical and cylindrical corrections), and presbyopia typically occurs with aging, usually reflected by a need for bifocals or multifocal lenses rather than a straightforward +1.50 prescription for both eyes