There may be various tests that you have experienced at an eye exam and wondered what they are for. Having a bright light shined into your eyes may be an example. Such as test is used to help test the refractive error of your eye, and it's known as a retinoscopy exam. By merely looking at the way light reflects off your retina, your eye care professional can decide whether you are nearsighted, farsighted or have astigmatism, and can also get a pretty good reading on the prescription required to correct your vision.
How well your eyes focus under the circumstance we create during the exam is the main thing we look for. When light shines into your eye using a retinoscope, a reddish orange light reflects off your retina, through your pupil. Eye doctors call this the red reflex. The degree at which the retinoscope's light refracts off your retina, which is what eye care professionals call your focal length, is the thing that tells us how well your eye can focus. If it becomes clear that you can't focus correctly, we hold up a variety of prescription lenses in front of your eye to determine which one corrects your vision.
Your optometrist will run your exam in a dark room. You will usually be instructed to focus on something behind the doctor. Because a patient doesn't need to read eye charts during a retinoscopy exam, it means that it's also a really great way to determine an accurate prescription for kids who might struggle with speech, or others who might be speech-impaired.