Eye diseases in travelers.

Travelling has been growing in popularity over the last several decades. Eye diseases, e.g. decreased visual acuity, inflammatory or degenerative lesions, chronic diseases or eye trauma, affect all groups of travelers. The main risk factors contributing to the manifestation or exacerbation of common ocular diseases include exposure to dry air (inside the airplane cabin or in air-conditioned hotel rooms), exposure to chlorinated or salty water (swimming/bathing in swimming pools or in the sea), and sudden changes in the weather conditions. In addition, travelers to tropical destinations are at risk of ocular diseases which are rarely seen in temperate climate, e.g. onchocerciasis, loiasis, gnatostomosis, African trypanosomosis, or trachoma. The most common condition of the eye seen in travelers is conjunctivitis; it may be either of cosmopolitan (bacterial or viral infections, allergic inflammation) or tropical etiology, e.g. arboviral infections (zika, chikungunya). Given the fact that a large proportion of the general population have decreased visual acuity and many of them wear contact lenses rather than glasses, keratitis has become a common health problem among travelers as well; the major risk factors in such cases include sleeping in contact lenses, prolonged exposure to air-conditioning, working with a computer or swimming/bathing in microbiologically contaminated water (e.g. Acanthoamoeba protozoa). Conditions affecting the cornea, conjunctiva or lens may also occur due to excessive exposure to solar radiation, especially if travelers wear glasses without a UV protection.