Dry eyes are caused by a lack of adequate tears. Your tears are a complex mixture of water, fatty oils and mucus. This mixture helps make the surface of your eyes smooth and clear, and it helps protect your eyes from infection.
For some people, the cause of dry eyes is decreased tear production. For others it's increased tear evaporation and an imbalance in the makeup of your tears.
Decreased tear production
Dry eyes can occur when you're unable to produce enough tears. The medical term for this condition is keratoconjunctivitis sicca(ker-uh-toe-kun-junk-tih-VY-tis SIK-uh). Common causes of decreased tear production include:
- Certain medical conditions, including diabetes, rheumatoid arthritis, lupus, scleroderma, Sjogren's syndrome, thyroid disorders and vitamin A deficiency
- Certain medications, including antihistamines, decongestants, hormone replacement therapy, antidepressants, and drugs for high blood pressure, acne, birth control and Parkinson's disease
- Laser eye surgery, though symptoms of dry eyes related to this procedure are usually temporary
- Tear gland damage from inflammation or radiation
Increased tear evaporation
Common causes of increased tear evaporation include:
- Wind, smoke or dry air
- Blinking less often, which tends to occur when you're concentrating, for example, while reading, driving or working at a computer
- Eyelid problems, such as out-turning of the lids (ectropion) and in-turning of the lids (entropion)
Imbalance in tear composition
The tear film has three basic layers: oil, water and mucus. Problems with any of these layers can cause dry eyes. For example, the oil film produced by small glands on the edge of your eyelids (meibomian glands) might become clogged. Blocked meibomian glands are more common in people with inflammation along the edge of their eyelids (blepharitis), rosacea or other skin disorders.
July 24, 2015
- AskMayoExpert. Dry eye disease. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2014.
- Dry eye. American Optometric Association. http://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/dry-eye?sso=y. Accessed June 2, 2015.
- What is dry eye? American Academy of Ophthalmology. www.geteyesmart.org/eyesmart/diseases/dry-eye/index.cfm. Accessed June 2, 2015.
- Yao W, et al. Dry eye syndrome: An update in office management. The American Journal of Medicine. 2011;124:1016.
- Stevenson W, et al. Dry eye disease. Archives of Ophthalmology. 2012;130:90.
- Shtein RM. Dry eyes. www.uptodate.com/home. Accessed June 2, 2015.
- Dry eye syndrome Summary Benchmark — 2014. American Academy of Ophthalmology. http://www.aao.org/summary-benchmark-detail/dry-eye-syndrome-summary-benchmark--october-2012. Accessed June 2, 2015.
- Rand AL, et al. Nutritional supplements for dry eye syndrome. Current Opinion in Ophthalmology. 2011;22:279.
- Facts about dry eye. National Eye Institute. http://www.nei.nih.gov/health/dryeye/dryeye.asp. Accessed June 2, 2015.
- Yanoff M, et al., eds. Dry eye. In: Ophthalmology. 4th ed. Edinburgh, U.K.: Mosby Elsevier; 2014. https://www.clinicalkey.com. Accessed June 2, 2015.
- Skalicky SE, et al. New agents for treating dry eye syndrome. Current Allergy and Asthma Reports. 2013;13:322.
- Toyos R, et al. Intense pulsed light treatment for dry eye disease due to meibomian gland dysfunction: A 3-year retrospective study. Photomedicine and Laser Surgery. 2015;33:41.
- Marcet MM, et al. Safety and efficacy of lacrimal drainage system plugs for dry eye syndrome. Ophthalmology. In press. Accessed June 2, 2015.
- Eye disorders. Natural Standard. https://naturalmedicines.therapeuticresearch.com. Accessed June 2, 2015.
- Castor bean. Natural Medicines Comprehensive Database. http://naturaldatabase.therapeuticresearch.com. Accessed June 2, 2015.
- Rocha EM, et al. Hormones and dry eye syndrome: An update on what we do and don't know. Current Opinion in Ophthalmology. 2013;24:348.
- Omega-3 fatty acid. Natural Medicines Comprehensive Database. http://naturaldatabase.therapeuticresearch.com. Accessed June 3, 2015.
- Vitamin A. Natural Medicines Comprehensive Database. http://naturaldatabase.therapeuticresearch.com. Accessed June 3, 2015.
- Finis D, et al. Evaluation of an automated thermodynamic treatment (LipiFlow) system for meibomian gland dysfunction: A prospective, randomized, observer-masked trial. Ocular Surface. 2014;2:146.
- Robertson DM (expert opinion). Mayo Clinic, Rochester, Minn. June, 12, 2015.
- Zouboulis CC, et al., eds. A treatment strategy for rosacea. In: Pathogenesis and Treatment of Acne and Rosacea. Berlin Heidelberg: Springer-Verlag, 2014.
- Preferred practice pattern: Dry eye syndrome. San Francisco, Calif.: American Academy of Ophthalmology. http://one.aao.org/CE/PracticeGuidelines/PPP_Content.aspx?cid=127dbdce-4271-471a-b6d9-464b9d15b748. Accessed June 14, 2012.