Early onset of presbyopia.
Of the 800 presbyopes studied, 286 (35.75%) entered presbyopia at or before the age of 38 years. About 63% of these patients lived in rural areas and 37% in urban areas. Environmental conditions including high average temperature, much ultraviolet radiation, chronic deficiency of essential amino acids, and exposure to toxic factors, particularly hair dye, may play a significant role in precipitating the early onset of presbyopia.
D000328:Adult; D000367:Age Factors; D000368:Aged; D001831:Body Temperature; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D011305:Presbyopia / Q000209:etiology*; D013472:Sunlight / Q000009:adverse effects; D014329:Tropical Climate / Q000009:adverse effects