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Refractive Errors
Summary
The cornea and lens of your eye helps you focus. Refractive errors are vision problems that happen when the shape of the eye keeps you from focusing well. The cause could be the length of the eyeball (longer or shorter), changes in the shape of the cornea, or aging of the lens.
Four common refractive errors are:
- Myopia, or nearsightedness – clear vision close up but blurry in the distance
- Hyperopia, or farsightedness – clear vision in the distance but blurry
close up - Presbyopia – inability to focus close up as a result of aging
- Astigmatism – focus problems caused by the cornea
The most common symptom is blurred vision. Other symptoms may include double vision, haziness, glare or halos around bright lights, squinting, headaches, or eye strain.
Glasses or contact lenses can usually correct refractive errors. Laser eye surgery may also be a possibility.
NIH: National Eye Institute
National Eye Institute
Related Issues
- Abnormal Head Position American Association for Pediatric Ophthalmology and Strabismus
- What Are the Risks and How Can I Find the Right Doctor for Me? (Refractive Surgery) Food and Drug Administration
Find an Expert
- American Optometric Association American Optometric Association
- Find a Doctor of Optometry American Optometric Association
- Find an Ophthalmologist American Academy of Ophthalmology
- Finding an Eye Doctor National Eye Institute
- National Eye Institute National Eye Institute
Children
- Anisometropia American Association for Pediatric Ophthalmology and Strabismus
- Farsightedness (Hyperopia) (For Parents) Nemours Foundation
- Nearsightedness (Myopia) (For Parents) Nemours Foundation
- Photoscreening American Association for Pediatric Ophthalmology and Strabismus
- Refractive Errors in Children American Association for Pediatric Ophthalmology and Strabismus
- Treatment of Increasing Myopia in Children American Association for Pediatric Ophthalmology and Strabismus
- Your Child’s Vision Nemours Foundation
Start Here
- Astigmatism National Eye Institute
- Refractive Errors National Eye Institute
- Types of Refractive Errors National Eye Institute
Patient Handouts
- Astigmatism Medical Encyclopedia
- Farsightedness Medical Encyclopedia
- Nearsightedness Medical Encyclopedia
- Presbyopia Medical Encyclopedia
- Refraction Medical Encyclopedia
Specifics
- Astigmatism Mayo Foundation for Medical Education and Research
- Corneal Conditions National Eye Institute
- Presbyopia Mayo Foundation for Medical Education and Research
- Progressive (High) Myopia American Association for Pediatric Ophthalmology and Strabismus
Statistics and Research
- Blurry Worldview: Understanding Myopia National Institutes of Health
- Contact Lenses Slow Children’s Nearsightedness National Institutes of Health
- Eye Health Data and Statistics National Eye Institute
Clinical Trials
- ClinicalTrials.gov: Astigmatism National Institutes of Health
- ClinicalTrials.gov: Hyperopia National Institutes of Health
- ClinicalTrials.gov: Lenses, Intraocular National Institutes of Health
- ClinicalTrials.gov: Myopia National Institutes of Health
- ClinicalTrials.gov: Presbyopia National Institutes of Health
- ClinicalTrials.gov: Refractive Errors National Institutes of Health
Treatments and Therapies
- Cornea Transplant Mayo Foundation for Medical Education and Research
- Eye Wear: MedlinePlus Health Topic National Library of Medicine
- Laser Eye Surgery: MedlinePlus Health Topic National Library of Medicine
- Phakic Intraocular Lenses Food and Drug Administration
- What Is Refractive Surgery? American Academy of Ophthalmology
Encyclopedia
- Corneal transplant Medical Encyclopedia
- Corneal transplant – discharge Medical Encyclopedia
- Home vision tests Medical Encyclopedia
- Refractive corneal surgery – discharge Medical Encyclopedia
- Refractive corneal surgery – what to ask your doctor Medical Encyclopedia
- Standard eye exam Medical Encyclopedia
- Visual acuity test Medical Encyclopedia
Images
- Corneal transplant – series — Normal anatomy Medical Encyclopedia
Genetics
- Deafness and myopia syndrome: MedlinePlus Genetics National Library of Medicine
- Farsightedness: MedlinePlus Genetics National Library of Medicine
- Nearsightedness: MedlinePlus Genetics National Library of Medicine
Diagnosis and Tests
- Dilating Eye Drops American Association for Pediatric Ophthalmology and Strabismus
- Eye Exam and Vision Testing Basics American Academy of Ophthalmology
- Retinoscopy American Association for Pediatric Ophthalmology and Strabismus
- Vision Screening National Library of Medicine
Prevention and Risk Factors
- Get a Dilated Eye Exam National Eye Institute
Reference Desk
- How the Eyes Work National Eye Institute