Understanding Biprism: A Technique Used in Ophthalmology to Measure Refractive Error

Biprism is a technique used in ophthalmology to measure the refractive error of the eye. It involves using two prisms, one placed in front of the eye and the other behind the eye, to split the light entering the eye into two separate beams. The angle between these two beams is then measured to determine the refractive error of the eye.

Biprism is used to measure the refractive error of the eye in patients who have a high level of astigmatism or who have undergone refractive surgery. It is also used to monitor the progression of myopia in children and to detect amblyopia (lazy eye) in young children.

The biprism test is performed by an ophthalmologist or optometrist and typically takes about 15-30 minutes to complete. The patient is seated in a chair and asked to look through a phoropter, which contains a series of lenses that are flipped back and forth to measure the refractive error of the eye. The biprism prisms are placed in front of and behind the eye and the angle between the two beams is measured using a retinoscope or an autorefractor.

Overall, biprism is a valuable tool for measuring the refractive error of the eye and detecting various eye conditions. It provides accurate and reliable measurements that can help ophthalmologists and optometrists prescribe appropriate corrective lenses or other treatments to improve vision.