Refractive error video
Refractive error video transcript
Refractive errors are vision problems that occur when the eye cannot focus light directly onto the retina. This inability to focus light results in blurred vision.
The process of vision starts with light rays entering the eye. Different structures of the eye bend light so that it comes to a focus on the retina.
The retina is tissue at the back of the eye. It’s filled with light-sensitive cells that convert light into signals. The signals are then sent to the brain and processed as an image.
A refractive error occurs when incoming light does not properly focus on the retina.
The three primary refractive errors are myopia, hyperopia and astigmatism.
Myopia, also called nearsightedness, usually occurs when the eyeball’s length is a little longer than it should be. This causes light to focus in front of the retina and results in blurry distance vision.
Hyperopia, also called farsightedness, usually happens when the eyeballs are a little shorter than they should be. Because of this, light comes to a focus behind the retina, and causes blurry close-up vision.
Astigmatism is a refractive error that usually occurs due to the cornea, which is the clear, front surface of the eye. In people with astigmatism, the cornea is not perfectly spherical, so when light enters through the cornea, it focuses at several different points, instead of focusing on one point. Astigmatism can make vision blurry at near and far distances.
To learn more about refractive errors, visit AllAboutVision.com.
Page published on Friday, March 4, 2022
