In the 1980’s, myopia was the most common eye problem in Ohio, followed hyperopia, or farsightedness, and glaucoma, in that order.  The incidence for both hyperopia and glaucoma increases with age, but the incidence rate for myopia is the same for people of all ages.  The average age of the population of Ohio residents is expected to increase between 1990 and 2010.

Which of the following conclusions can be most properly drawn about chronic medical conditions in Ohio from the information given above?


A.  Myopia will be more common than either hyperopia or glaucoma by 2010

B.  Hyperopia will be the most common eye condition in 2010.

C.  The average age of people suffering from myopia will increase between 1990 and 2010.

D.  Fewer people will suffer from myopia in 2000 than suffered from it in 1980.

E.  A majority of the population will suffer from at least one of the medical conditions mentioned above by the year 2010.
 
The best answer is C.  Given that the incidence rate for myopia is the same for people of all ages, and that the average age of the population will increase, it follows that the average age of people suffering from myopia will increase.