A Contact Lens Is Made of Plastic with an Index

Multiple Choice

A contact lens is made of plastic with an index of refraction 1.50.The lens has an outer radius of curvature of + 1.65 cm and an inner radius of curvature of + 5.85 cm.What is its focal length?

A) -4.60 cm
B) +1.53 cm
C) +2.57 cm
D) +4.60 cm
E) -2.57 cm ​