AIM: To understand the risk factors of dry eye for people under age 40 to reduce the incidence of dry eye, provide a theoretical basis for reducing the harm of dry eye.

METHODS:A total of 440 patients aged below 40 were selected from Apr. to Sep.2015 in Shanxi Eye Hospital for the study. After obtaining the informed consent of the patient, they underwent face to face interviews with questionnaires to obtain relevant information. The tear break-up time, Schirmer I test, corneal fluorescein staining were measured and recorded. A total of 259 dry eye patients were pathological group, and the remaining 181 cases were the control group. A case control study was used.

RESULTS: Four hundred and forty cases included 205 male(46.6%)and 235 female(53.4%)patients diagnosed 259 cases(58.9%)with dry eye. The result of Logistic regression analysis revealed that refractive errors(OR=4.582, 95%CI=2.789-7.562), daily reading and writing time more than 4h(OR=1.380, 95%CI=1.111-1.715), non-standard reading and writing posture(OR=4.202, 95%CI=2.531-6.977), wearing contact lenses(OR=3.374, 95%CI=1.837-6.196), combination of ophthalmic(OR=3.749, 95%CI=1.608-8.740), rhinitis(OR=2.244, 95%CI=1.412-4.410), conjunctivitis(OR=3.971, 95%CI=2.005-7.866), LASIK surgery(OR=4.494, 95%CI=0.988-20.447), neighborhood within 1 km has pollution building(OR=3.039, 95%CI=1.185-7.796)were risk factors for dry eye.

CONCLUSION: The prevalence of ophthalmology clinic under the age of 40 in patients with dry eye is far higher than the general prevalence. The results indicate that people's bad habits, behavior and environmental pollution are risk factors for dry eye.