title: Contact lens wear in dry environments.
abstract: The relation between relative humidity at the place of work and subjective discomfort as well as a number of objective parameters was studied in 34 contact lens wearers. Subjects in a low relative humidity (less than about 30%) showed significantly shorter BUT on the lens and more prominent lens deposits than subjects in a higher relative humidity (greater than 40%). A short BUT on the lens was associated with lens deposits (and vice versa) and restricted lens movements. Discomfort was particularly prominent when humidity was less than about 25%, when BUT on the lens was less than 20 sec, and when lens deposits were present. An experiment where relative humidity was manipulated between about 20 and 50% showed that subjects with a short BUT on the lens and prominent lens deposits were much more sensitive to a low relative humidity than other subjects. Enzymatic cleaners, frequent lens replacements, and loose fits were valuable to lessen discomfort.
mesh_terms: D000328:Adult; D000367:Age Factors; D002980:Climate; D003263:Contact Lenses, Hydrophilic / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006813:Humidity; D008027:Light; D008297:Male; D008834:Microclimate; D012737:Sex Factors; D013696:Temperature; D013997:Time Factors