Technical Information
Professional optical specifications and fitting guides to support accurate lens selection and ordering.
Compare Special Base Options
For steeper curved frame selections, a suggested base curve is recommended to optimize the finished prescription result.
Lens Material Thickness Comparison
Compare the edge thickness of different GT Optical Lab lens materials under identical conditions.
Diameter Control Sliding Scale
Use the diameter control sliding scale to determine the smallest lens blank that safely accommodates the selected frame.
Diameter Reduction
Diameter reduction is recommended for hyperopic prescriptions whenever frame measurements allow.
Progressive Sliding Scale
Use these fitting charts to support accurate progressive lens positioning, corridor selection, and frame compatibility.
Tint Color Scale
The tint color scale provides reference tones for standard index lenses.
Explanation of Progressive Engravings
Progressive engravings help identify lens design, corridor height, fitting height, index, addition, and brand markings.
Technical Information Chart
Review key lens material specifications including index, density, Abbe value, and UV cut information.
