Horizontal Segment Design
The StraighTop is a
translating/alternating multifocal design with a large, superior, front-surface
distance-vision segment and a large, inferior, front surface “plus” power
near-vision segment. These segments
are joined by a horizontal junction which is usually located 1.0 mm below the
centerline of the lens. The
StraighTop can accommodate spherical, aspheric or toric base curve geometry.
This design is prism-ballasted to maintain alignment, but also maintains clear near acuity with up to 20 degrees of lens rotation.
Diameters: 8.50 mm to
Diameters: 8.50 mm to 10.0 mm
Base Curve: 6.50 mm to 8.44 mm
Distance: -20.0 D to +6.00 D
Add Power: +0.75 to +3.00 D
The RGP Multifocal Specialists