What are the extreme lens diameters?

What are the extreme lens diameters?

• A. 6.0 - 18.0 mm
• B. 10.0 - 20.0 mm
• C. 8.0 - 16.0 mm
• D. 12.0 - 14.0 mm

Answer: (A)

Diameter is the horizontal width of the lens across the eye. When we talk about the extreme sizes used in soft contact lens practice, the practical range runs from about 6.0 mm up to about 18.0 mm. The 6.0 mm end covers very small corneas or specialized fits, while the 18.0 mm end accommodates larger eye anatomies and ensures the lens can sit with proper centration and clearance. This span captures the full spectrum clinicians commonly encounter, making 6.0–18.0 mm the best representation of extreme lens diameters. The other ranges either miss one end of the spectrum or stay within a narrower middle range and don’t reflect the full breadth of fittings.

Diameter is the horizontal width of the lens across the eye. When we talk about the extreme sizes used in soft contact lens practice, the practical range runs from about 6.0 mm up to about 18.0 mm. The 6.0 mm end covers very small corneas or specialized fits, while the 18.0 mm end accommodates larger eye anatomies and ensures the lens can sit with proper centration and clearance. This span captures the full spectrum clinicians commonly encounter, making 6.0–18.0 mm the best representation of extreme lens diameters. The other ranges either miss one end of the spectrum or stay within a narrower middle range and don’t reflect the full breadth of fittings.