What does refraction in an eye exam mean?

Refraction is the bending of light rays as they pass through one object to another. The cornea and lens bend (refract) light rays to focus them on the retina. When the shape of the eye changes, it also changes the way the light rays bend and focus — and that can cause blurry vision.

What is refraction assessment?

During a refraction assessment, your doctor asks you to look through a masklike device (phoropter) that contains wheels that hold lenses of different strengths to help determine which combination gives you the sharpest vision.

Why do I need a refraction test?

An automated refraction eye test is one of the ways we can measure how well you can see and helps your optometrist to determine the prescription (lens strength) you need to see clearly.

How long does an eye refraction test take?

You’ll also want to carry a quick list of your family medical history and vision loss symptoms to discuss with your eye doctor. Most eye exams last between one hour to an hour and a half. During this time, the optometrist will assess your eyes and see if prescription eyewear would benefit you.

What does refraction mean in an eye exam?

In physics, “refraction” is the mechanism that bends the path of light through the eye. In an eye exam, the term refraction is the determination of the ideal correction of refractive error.

What is refraction testing in an eye checkup?

A refraction test is usually given as part of a routine eye examination. It may also be called a vision test. A refractive error means that the light is not bending properly when it passes through the lens of your eye . The refraction test will tell your doctor what prescription lens you should use in order to have 20/20 vision.

What causes refraction in eyes?

A refractive disorder is an ocular condition caused by changes in the shape of the eye, which prevents light from being focused sharply on the retina, creating unclear images. The causes may range from congenital shortening or lengthening of the eyeball through variations in the shape of the cornea, to anomalies of the lens.

How is refraction related to human eye?

In a mouse or human eye, most of the refraction occurs at the interface between air and cornea because of the refractive difference between the two media. The refractive index of air is approximately 1.0, and the cornea is approximately 1.3.