๐ Ophthalmic Optics & Lens Design
Optical Power (Diopter vs Focal Length) Converter
Convert lens refracting power ($P = 1/f$) and focal length across $\text{Diopters}$ ($\text{D} = \text{m}^{-1}$), Millimeters ($\text{mm}$), Centimeters ($\text{cm}$), and $\text{Inches}$.
๐ Reading (+2.00 D)
๐๏ธ Myopia (-3.50 D)
๐ Magnifier (+10.0 D)
๐ท 50mm Prime Lens
๐ญ 200mm Telephoto
Input Lens Parameter
Focal Length (mm)
500.0 mm
Diopters (D)
2.00 D
Centimeters (cm)
50.00 cm
Inches (in)
19.69 in
๐ก Diopter to Focal Length Formula:
$$P = \frac{1}{f(\text{m})} \implies f(\text{mm}) = \frac{1000}{P(\text{D})} \implies 2.00\text{ D} = 500\text{ mm}$$
Understanding Optical Power & Diopters
Optical power ($P$) is the degree to which a lens or curved mirror converges or diverges light, defined as the reciprocal of its focal length:
- Definition: $$P = \frac{1}{f} \text{ (in } \text{m}^{-1} = \text{Diopters)}$$
- Positive vs Negative:
- Positive Diopters ($+D$): Converging convex lenses used to correct hyperopia (farsightedness) and presbyopia (reading glasses).
- Negative Diopters ($-D$): Diverging concave lenses used to correct myopia (nearsightedness).
- Thin Lens Addition: The total optical power of two thin lenses in direct contact is simple addition: $P_{\text{total}} = P_1 + P_2$.