Q: What is Presbyopia?  (presby - old; opia - eyes)

A: Presbyopia refers to the gradual loss of accommodation--the ability to focus near objects.  It typically begins at about 40 years of age and ends at about 50 to 55 years of age.  Although once thought to be the result of an aging focusing muscle, it is now agreed to be a result of a hardening of the human crystalline lens.  Infants are born with flexible lenses, due to a prevalence of an elastic protein appropriately named elastin. This production of this protein diminishes over the age of 40 and dwindles to produce a rigid lens by age 50 to 55.  

I am occasionally asked if eye exercises can help counteract the effects of presbyopia.  I often like to use the analogy of the strongest man in the world trying to change the shape of a rock.  (It's a bit of a stretch but you get the idea.)  Although there is a relation between the strength of the ciliary body (focusing) muscle and accommodation, focusing near objects is a product of both the flexibility of the lens and the action of the muscle.  This should not be confused with the less common muscle problems which do affect some people under the age of 40.  There are problems related to weakness, inaccuracy, or ill-sustain of the focusing muscle which do respond to certain eye exercises, but most people are born with  perfectly functioning ciliary body muscles and will get enough exercise through typical daily use of their eyes.