Refractive errors are common eye issues that can cause blurry or distorted vision. Treatment usually involves wearing glasses or contact lenses or getting procedures, such as laser eye surgery, to correct the error.
Refractive errors may occur due to atypical shapes of the eyeball or cornea. They can also be due to natural changes in the eye’s lens as a person ages.
Doctors can diagnose refractive errors as part of a routine or dilated eye exam. Seeking treatment is important, as refractive errors can have an adverse effect on someone’s well-being.
There are four
- Myopia (nearsightedness): Distant objects may look blurry or out of focus.
- Hyperopia (farsightedness): Nearby objects may look blurry or out of focus.
- Astigmatism: A problem with the shape of the eye that can make near or distant objects look out of focus or distorted.
- Presbyopia: Nearby objects are blurry or hard to see because the eye’s lens hardens with age. This is different from hyperopia; presbyopia
will affect everyone as they age, even if they already have another refractive error.
A 2017 review suggests that astigmatism is the most common refractive error globally, followed by farsightedness and nearsightedness. The prevalence of various refractive errors varies globally.
The authors suggest that nearsightedness and astigmatism are most common among adults in Southeast Asia. Farsightedness is most common among children and adults in the Americas.
The
- headache
- squinting or frowning
- eye discomfort
- eye fatigue
- hazy vision
- double vision
- a halo or glare around bright lights
- difficulty focusing on computer screens or when reading
People may also experience these symptoms if they already wear contact lenses or eyeglasses. This may indicate that they need a new prescription.
In children, caregivers may notice excessive blinking or rubbing of the eyes.
Refraction refers to how light rays bend when they pass through an object.
A typical eye has a round, spherical surface. The cornea is the clear outer surface of the eye. The lens is the clear inner part of the eye.
The cornea and lens refract light rays toward the retina, a sensitive layer of tissue at the back of the eye, to send a sharp image to the brain.
Refractive errors occur when the shape, length, or characteristics of the eye affect this process. Causes may
- the eyeball is too long or short
- atypical cornea shape
- natural aging of the lens, making it harder and less flexible
The exact cause may depend on the type of refractive error someone has.
Eye doctors can diagnose refractive errors
They may also use drops to widen the pupil of the eye, also called a dilation eye exam. This can help the eye doctor check for any diseases or eye conditions.
The
- African American people over 45 years old
- people over 60 years
- people with a family history of glaucoma
People with diabetes or high blood pressure may need dilated eye exams at least once a year.
Getting a diagnosis for refractive errors is important. Without treatment, refractive errors may affect a person’s:
- well-being
- academic performance
- workplace participation and productivity
- social life
Doctors can correct refractive errors with one of the
- eyeglasses
- contact lenses
- procedures such as laser eye surgery
Eyeglasses are the
In
If someone continues to have symptoms of refraction errors, such as blurry vision, after getting glasses or contact lenses, they may need a different prescription.
It is
- spending at least 90 minutes outside each day
- taking regular breaks from tasks that involve looking at nearby items, such as reading or screens
- using any prescription eyeglasses as an eye doctor instructs
People can speak with their eye doctor about other methods to improve and protect their general eye health.
Doctors can identify refractive errors at routine eye exams. However, if someone notices symptoms between eye exams, they should contact their eye doctor for a checkup.
Without treatment, someone with a refractive error may have difficulty seeing clearly. This can affect all areas of life, including work or school, driving or transport, and social aspects.
Refractive errors may cause children to squint or frown, blink excessively, or rub their eyes. Parents and caregivers should book an eye exam for the child if they notice these signs.
How common are refractive errors?
A 2017 review states that refractive errors are the most common eye problem affecting all ages. The prevalence of different types varies globally.
The
How do eyeglasses correct refractive errors?
Eyeglasses use different types of lenses to correct refractive errors. Spherical lenses can correct nearsightedness and farsightedness. Cylindrical lenses can correct astigmatism.
The numbers on a person’s eyeglasses prescription refer to the power of spherical correction and cylindrical correction and the axis of the cylinder.
What are the advantages and disadvantages of contact lenses for refractive errors?
Some people may prefer contact lenses to correct refractive errors because they find them more convenient. They can stay in place when playing sports or wearing sunglasses. Contact lenses can also improve peripheral or side vision.
However, contact lenses can cause eye infections if a person does not use and clean them properly.
Refractive errors are a common eye problem. They can cause blurry vision and difficulty seeing. The type of refractive error someone has may affect their symptoms.
Although it is not possible to entirely prevent refractive errors, treatment can correct this visual problem. People can use eyeglasses, contact lenses, or procedures such as laser eye surgery.
An eye doctor can diagnose refraction errors using an eye exam. People should contact their eye doctor if they experience blurry vision and other eye symptoms between eye exams.