My Improving Eye Roundness

During the past five years my eyes have been getting rounder.

Vision prescriptions involve three measurements: sphere, cylinder, and axis.

(It sounds like a math test, doesn't it?)

My sphere measurement has remained constant at -0.75 which means I am slightly and unchangingly myopic.  I wear my glasses when driving or when I go to a movie.  My prescription is minor enough that even glass lenses are light and comfortable, so I always get glass lenses to avoid lens scratches.

My cylinder measurements have decreased, which means my eyes are getting rounder.  In 2007 they were -1.00 and -0.75 (right and left eye).  In 2009 they were -0.75 and -0.75.  Two weeks ago they were -0.5 and -0.5.

The axis measurements have also changed slightly: 172 and 22, then 164 and 20, then 165 and 20.