http://www.my-gcsescience.com/revision/separate/focal-length-and-lens-power
Information about using the lens power equation, describe the factors that determine the focal length of a lens, an explaining the effect of refractive index on the size and shape of the lens for a given focal length.
Specification reference: P3.1.4 The Eye
- The power of a lens is given by: P = 1/f where P is power in dioptres, D, and f is focal length in metres, m
- You should know that the power of a converging lens is positive and the power of a diverging lens is negative
- For a given focal length, the greater the refractive index, the flatter the lens. This means that the lens can be manufactured thinner.
