Presbyopia has long been recognized as a condition that attacks human beings beyond middle age and gradually increases until the age of 60 years, after which it is likely to remain stationary. This recession of near point for vision is considered a normal process in the life cycle of the tissues of the eye. It is apparently associated with a change in the tissue of the lens in the direction of increased hardness and lessened elasticity. Because of this inability of the lens to stretch or relax in response to the demand for accommodation, the ability to see printed matter or objects held close to the eye is decreased.
Not long ago Steinhaus1 developed the conception that a definite relationship exists between aging of the lens of the eye and aging of the body in general. He pointed out that Kronfeld had previously demonstrated that the energy requirements of