REFRACTIVE ERRORS

  Myopia (nearsightedness) affects more than 30.5 million Americans age 40 and 

older (26%) (Prevent Blindness, 2002). 

 Hyperopia (farsightedness) affects 12 million Americans age 40 and older (10%) 

  (Prevent Blindness America, 2002). 

 It is estimated that between 1% and 4% of the childhood population are affected 

by strabismus and 1% to 2% suffer from amblyopia (National Advisory Eye 

Council, 1993). 

  In the United States, less than 2% of all children beginning school (age 5) are 

myopic.  By the end of grade school (age 11 or 12) more than 15% are myopic. 

By adulthood, about 25% Americans are myopic thereby requiring some form of 

optical correction to see clearly beyond an arm s length (National Advisory Eye 

Council, 1993, p. 247). 

  Although amblyopia, strabismus, nystagmus, and myopia seldom cause legal 

blindness they produce substantial visual loss that interferes with learning and 

working, and the overall quality of life (National Advisory Eye Council, 1993). 

25