Radius/Diopter Conversion Calculator

Converting between Radius and Diopters

In optometry, understanding the relationship between the radius of curvature and diopter values is fundamental for accurately fitting contact lenses and prescribing corrective lenses. The diopter value of a lens indicates its refractive power, which is the degree to which the lens can bend light to focus on the retina. This value is inversely related to the radius of curvature of the lens's surface, measured in millimeters. A steeper curve (shorter radius) results in a higher diopter value, while a flatter curve (longer radius) results in a lower diopter value. Converting between these two measurements is essential when tailoring contact lenses to fit the unique curvature of a patient's cornea. For instance, when a lens needs to be adjusted from a spectacle prescription to a contact lens prescription, knowing how to accurately convert between radius and diopters ensures that the contact lenses will sit correctly on the cornea and provide the intended visual correction. This conversion is not only crucial for the comfort and health of the eye but also for achieving optimal visual acuity. Thus, proficiency in radius and diopter conversions is a vital skill for optometrists, enabling them to provide personalized and precise vision care.

Radius/Diopter Conversions

mm to D
Radius (mm)Diopters (D)
D to mm
Diopters (D)Radius (mm)