A near sighted person cannot see objects clearly that are beyond 50 cm from his eye. Determine the power of the glasses that will enable him to see distant objects clearly.

• A

  $-1.0\text{ D}$

• B

  $-2.0\text{ D}$

• C

  $-3.0\text{ D}$

• D

  $-4.0\text{ D}$