Presbyopia is due to the lens in your eye no longer being able to change its shape in order to focus on near objects. When you are looking into the distance the lens inside your eye is flat and relaxed. When you look at something up close the lens inside your eye changes shape becoming more steeply curved on its front and back surfaces enabling things at close range to come into sharp focus. This process occurs instantaneously, without you being aware that any change has occurred. Throughout life the lens constantly grows, becoming denser. Thereby its ability to change shape for near focus gradually reduces with age. You become aware of this as a receding near point of focus. People often comment that their “arms are not long enough” or that “the print in phone books is getting smaller”.
