What is a refraction?
A refraction is a test where the doctor determines your prescription for glasses or contacts. The verb refract means to bend light. Your doctor of optometry will refract using a combination of tests to ensure your prescription for glasses is perfect. A Subjective refraction is where the eye doctor asks you, “What’s better one or two?” An objective refraction includes the tests that patients do not need to respond such as retinoscopy or auto-refraction.
An auto-refractor is a machine that shines a light in your eye and estimates how blurry your vision is. In retinoscopy, the doctor shines a light in your eye and checks which lens brings the light into focus. That is how doctors can accurately determine the prescription of even babies. Astigmatism, myopia, hyperopia and presbyopia are the types of refractive errors.
Do you need glasses?
- Refractive errors are the most common cause of blurry vision. They affect 25% of children and 80% of adults in the USA
- Refractive errors occur when the eye isn’t shaped perfectly to focus your vision. It is not a disease
- Your glasses prescription must be checked every 1-2 years due to small changes in the shape of the eye
- Glasses are the easiest way to correct the blurry vision. Glasses are usually permanent because they do not change the shape of the eye
- Contacts are an option starting at 8-12 years old, but you must also have glasses to rest your eyes
- Laser eye surgery (LASIK) is an option after 21 years old and the prescription is stable for 3 years
- If your glasses prescription is high, you will need a partial (lower) prescription for adaptation. The lenses are changed in 3-6 months.
- Myopia can get worse due to heredity or excessive near work such as reading or computers
- Myopia occurs when the eye grows too long and most progression occurs before 21 years old
- This can stretch the retina and cause eye health problems
- Myopia is permanent and it is important to control the progression of myopia at a young