Sex, age and the birefringence of the human crystalline lens

Measurements were made of the birefringence of intact human crystalline lenses and of single lens fibres in the age range of 4 to 93 years. Birefringence changes were observed when the lenses were stressed. It was possible to obtain high correlations between the optical and mechanical properties of the lenses. Male and female lenses had significantly different properties, the latter pointing to a greater disposition to irreversible changes under minimal stress. Age produced systematic changes. Both stress and age parameters are analyzed.