Retinoscopy is a handheld device used by eyecare professionals to determine whether your eyes are “20/20,” or have difficulties in seeing things up close or far away. Technically speaking, retina scopes help eye doctors determine if you have “refractive errors” like nearsightedness or farsightedness.
By shining a light back and forth across your eye, optometrists are able to determine (usually with great accuracy) if your vision needs corrective lenses by “dialing” the retinoscope so that the light focuses properly at the back of the eye on the retina. The measurement taken by retinoscopes is often the first step toward using other calibrated eye exam equipment (phoropters and slit lamps, for example).
Retinoscopy is particularly handy for examining younger children and people with special needs who might have problems accurately describing “what’s wrong” with their vision. In addition, retinoscopes can be used to test how well your eyes work together.
How does a retinoscope work?
Your optometrist will dim the lights of the room and ask you to focus on a fixed point on a far wall. The eye doctor scans the light of the retinoscope back and forth across your eyes as fine adjustments are made to the lenses in the retina scope’s light source.
This usually takes only a few moments, and while your eye might water or tear slightly, the procedure is generally over before you know it.
If your optometrist discovers a potential vision problem, you’ll likely be asked to use other equipment to determine the exact prescription you need for corrective lenses, and look for general indicators of eye health, or potential eye problems.
Other high-tech equipment like autorefractors are becoming more common as well, as they take retinoscope measurements automatically in just a few seconds.
Special thanks to the EyeGlass Guide, for source material that aided in the creation of this website.