What they are
The cornea and lens of your eye bend (refract) light to focus it on the retina. A refractive error happens when the shape of the eye keeps light from focusing properly on the retina — and vision turns blurry.
Causes
Refractive errors can happen when:
- the eyeball is too long or too short;
- the cornea changes shape;
- the lens becomes less flexible with age.
The four common types
| Type | What you notice |
|---|---|
| Nearsightedness (myopia) | faraway things look blurred |
| Farsightedness (hyperopia) | close-up things look blurred |
| Astigmatism | blurred or distorted vision at all distances; can make seeing at night harder |
| Presbyopia | trouble seeing up close as the lens stiffens with age; affects middle-aged and older adults, often from around age 45 |
Who gets them
Anyone — refractive errors are the most common vision problem. You're more likely to have one if family members wear glasses or contact lenses. Most types start in childhood or are present at birth; presbyopia is the exception, and nearly everyone develops it with age, typically from around 45.
Symptoms
Changes aren't always noticeable at first — one reason regular eye exams matter. The most common symptom is blurred vision. Others include:
- double vision or haziness;
- glare or halos around bright lights;
- squinting to see clearly;
- headaches;
- eye strain or tired eyes;
- trouble focusing when reading or using a computer.
Already wear glasses or contacts and notice these? You may need a new prescription — tell your eye care specialist.
Diagnosis
A comprehensive eye exam tests how well you see at different distances, with and without corrective lenses. Your provider may use drops to dilate (widen) your pupils to check for other eye conditions.
| Specialist | Role |
|---|---|
| Ophthalmologist | a medical doctor who treats eye diseases, prescribes glasses or contacts, and performs eye surgery |
| Optometrist | performs eye exams, diagnoses vision problems, prescribes glasses or contacts |
| Optician | fits and adjusts glasses or contacts from a prescription |
Treatment
Refractive errors are usually easy to correct, with:
- glasses;
- contact lenses;
- laser eye surgery, in some cases.
Your eye care specialist can help choose what suits your vision and lifestyle.
Sources
Based on the MedlinePlus health topic "Refractive Errors," National Library of Medicine, drawing on the National Eye Institute; a work of the United States government in the public domain.
Licence: CC0 1.0 (public domain) · Adapted from medlineplus.gov
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