" 10.A lens has a power of "-2.5" D.What is the focal length and nature of lens? "

The power of lens is 2.5 D . What is its focal length ?

Doctor has presecribed a lens having power + 1.5D. What will be the focal length of the lens ? What is the type of the lens and what must be the defect of vision ?

Doctor has prescribed a lens having power +1.5 D . What will be the focal length of the lens? What is the type of the lens and what must be the defect of vision?

If a spherical lens has a power of, -0.25 D, the focal length of this lens will be: