Lens Thickness Calculator

Formula

The formula to calculate the lens thickness (T) is:

\[ T = (n - 1) \cdot (R1 - R2) / 2 \]

Where:

\(T\) is the lens thickness
\(n\) is the refractive index of the lens material
\(R1\) is the radius of curvature of the first surface of the lens
\(R2\) is the radius of curvature of the second surface of the lens

What is Lens Thickness?

Lens thickness refers to the measurement of a lens from its front surface to its back surface at the thickest point. This measurement is typically given in millimeters and can vary greatly depending on the type of lens and its prescription strength. For example, a high prescription lens will typically be thicker than a low prescription lens. The thickness of a lens can also be influenced by the type of material used to make the lens, with some materials allowing for thinner lenses than others.

Example Calculation

Let's assume the following values:

Refractive index of the lens material (\(n\)) = 1.5
Radius of curvature of the first surface (\(R1\)) = 10 mm
Radius of curvature of the second surface (\(R2\)) = 5 mm

Using the formula:

\[ T = (1.5 - 1) \cdot (10 - 5) / 2 = 0.5 \cdot 5 / 2 = 1.25 \text{ mm} \]

The lens thickness (\(T\)) is 1.25 mm.