retinoscopic

Retinoscopy, also known as mirror refraction, is an objective method of determining refractive error in the eye. It is performed by a trained eye care professional, such as an optometrist or ophthalmologist, using a retinoscope and a set of lenses. The retinoscope projects a beam of light onto the patient's retina. The examiner then moves the light beam across the pupil while observing the reflex that returns from the retina. The movement and direction of this reflex, along with the properties of the light beam, indicate the type and amount of refractive error present.

To neutralize the reflex, the examiner introduces lenses of increasing power in front of the patient's eye. The goal is to find the lens power that causes the retinoscopic reflex to become neutral, meaning it moves directly with the examiner's hand movement without any apparent lag or lead. This neutralizing lens power corresponds to the refractive error. Retinoscopy is particularly useful for examining young children, individuals with communication difficulties, or those with nystagmus, as it does not rely on the patient's subjective responses. It is considered a fundamental skill in optometry and ophthalmology.