What procedure measures refractive error in patients?

Refractometry is the procedure specifically designed to measure refractive error in patients. This process involves using a device called a phoropter or an autorefractor to assess how light rays are bent as they enter the eye. By determining how the eye focuses light at various distances, refractometry can identify conditions such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism.

The measurements obtained from refractometry ultimately help in prescribing corrective lenses, ensuring that patients can achieve optimal visual clarity. Each patient's eye is analyzed to deduce the precise prescription needed, which is crucial for enhancing their quality of vision.

The other procedures mentioned do not specifically assess refractive errors. For instance, perimetry testing is employed to evaluate the visual field and check for blind spots or defects in vision. Fluorescein angiography is a method used to visualize the blood vessels in the retina, often to identify diseases affecting ocular circulation rather than refractive issues. Optical coherence tomography is a diagnostic imaging technique that captures high-resolution cross-sectional images of the retina, including its layers, but it does not measure how well a person's eyes are focusing light. Thus, refractometry stands out as the most appropriate and