Certified Ophthalmic Assistant Practice Exam

Which condition can be indicated by an inability to correctly identify letters on a vision chart?

1. Uncorrected refractive error

2. Strabismus

3. Astigmatism

4. Amblyopia

The correct answer is: Uncorrected refractive error

The inability to correctly identify letters on a vision chart is primarily associated with uncorrected refractive error. Refractive errors, such as myopia (nearsightedness) or hyperopia (farsightedness), occur when the shape of the eye prevents light from focusing directly on the retina, resulting in blurred vision. When individuals with uncorrected refractive errors attempt to read an eye chart, they often struggle to make out the letters clearly due to this focus problem. While conditions like strabismus, astigmatism, and amblyopia can also affect visual acuity, they do so in different ways and are not solely indicated by the difficulty of identifying letters on a vision chart. Strabismus involves misalignment of the eyes, leading to double vision or inhibition of depth perception rather than direct issues with clarity on a chart. Astigmatism, a specific type of refractive error, can certainly lead to problems reading the chart, but it is a distinct condition, often categorized under refractive errors in a broader sense. Amblyopia, or "lazy eye," may lead to poor vision in one eye that is not correctable with glasses or contact lenses, and while it may affect letter recognition on the chart,