Patients who already wear RGPs and do most of their work at a desk usually do well with a translating design. Richard W. Baker, O.D., F.A.A.O., says he�s had success fitting patients who are wearing single-vision RGPs for distance and also those monovision patients who need a higher reading add. He�s also successfully refitted patients wearing aspheric rigid lenses with an add in the +1.50D range who needed about a half-diopter more add.

Dr. Baker says he always uses diagnostic lenses to evaluate patients for this design. The lens fits best when the base curve is flatter than the corneal curve by the amounts specified in the fitting guide. The

lens must position correctly. It should translate about 2 mm when the patient looks down to read, and return quickly to the resting position. The segment should be 1.5 mm below the visual axis in primary gaze.

Using a handheld trial lenses when over-refracting to determine the final lens prescription gives you a more accurate contact lens prescription than simply calculating the contact lens power from the spectacle correction, Dr. Baker adds.