Introduction to Vision Rehabilitation Practice Test

Starting point for refraction relies on measurements that do not depend on how the patient reports their vision. Objective tests provide a numerical sense of refractive error without needing patient feedback. Keratometry measures the cornea’s curvature and converts it into a corneal power estimate, which helps predict refractive error and astigmatism. Retinoscopy observes the reflex from the retina as a light source is swept; when the reflex is neutralized, you get an estimate of refractive error independent of the patient’s responses. Pinhole acuity, on the other hand, is a functional test that depends on the patient’s subjective perception of clarity through a pinhole. It indicates whether reducing blur might help, but it does not yield a numeric starting lens power. Large lens changes are part of the refinement process during refraction and not a direct objective measurement either. Therefore, pinhole acuity is not an objective starting-point measurement.