In contact lens fitting, which zone in a lenticular lens has no refractive power?

In contact lens fitting, which zone in a lenticular lens has no refractive power?

• A. Central zone
• B. Periphery
• C. Lenticular zone
• D. Optical zone

Answer: (C)

In a lenticular lens, the zone that is specifically designed to have no refractive power is the lenticular zone. This region is often located at the edges of a contact lens, where the refractive power transitions from the central portion to an area that gradually blends into the overall lens shape. The purpose of the lenticular zone is to create a thinner edge profile for the lens, aiding in comfort and aesthetics while minimizing distortion. This zone does not contribute to the corrective optical power of the lens, allowing for a smooth transition between the correct refractive area of the optical zone and the lens’s edge. Other zones, such as the central zone, periphery, and optical zone, each hold specific refractive qualities that contribute to focusing light correctly onto the retina. Understanding the role of the lenticular zone is crucial for effective contact lens fitting, as it directly impacts the lens's overall performance and the wearer’s comfort.

In a lenticular lens, the zone that is specifically designed to have no refractive power is the lenticular zone. This region is often located at the edges of a contact lens, where the refractive power transitions from the central portion to an area that gradually blends into the overall lens shape.

The purpose of the lenticular zone is to create a thinner edge profile for the lens, aiding in comfort and aesthetics while minimizing distortion. This zone does not contribute to the corrective optical power of the lens, allowing for a smooth transition between the correct refractive area of the optical zone and the lens’s edge.

Other zones, such as the central zone, periphery, and optical zone, each hold specific refractive qualities that contribute to focusing light correctly onto the retina. Understanding the role of the lenticular zone is crucial for effective contact lens fitting, as it directly impacts the lens's overall performance and the wearer’s comfort.