Accommodation: Changes that occur in the shape of the lens for seeing objects clearly at near distances
Lasik: A type of laser procedure on the eye to correct refractive errors and presbyopia by reshaping the cornea.
Multiple sclerosis: A disease of the central nervous system wherein there is a loss of the outer covering of the nerve cells
Myasthenia gravis: A disorder involving the junction between nerves and muscles (neuromuscular junction) resulting in weakness of muscles