presbyopia

This is the process by which you become more reliant on reading glasses as you get older. When we are born, we have a clear lens that sits inside our eye.  This lens is flexible and can change shape to help us focus.  The lens can “flatten” like a pancake and allow a child to see a distant mountain, or the lens can “round out” like a marble and allow a child to focus on extremely close objects such as a butterfly landing on the nose. This lens shaping ability is called “accommodation.” As we get older, the lens begins to stiffen a little bit and doesn’t go “round” as easily as it used to.  Once we hit 40 years of age, the lens is so rigid that we have a hard time reading things close-up and find ourselves holding books further and further away.  As the lens continues to harden we require bifocals or reading glasses for near tasks.  This process of lens stiffening and the loss of focal range is called presbyopia and is a normal aging change in our eye.