ASTIGMATISM: Material Selection Ed Bennett OD, MSEd, FAAO, FSLS Material Selection Material Selection – based upon oxygen permeability – has been divided into three categories, all pertaining to fluoro-silicone/acrylate materials:1 Low (25 – 49). These materials have...
ASTIGMATISM: Definition Jessica Conroy OD, FAAO When thinking about corneal rigid gas permeable (GP) lenses, “Astigmatism” is defined in terms of both “residual astigmatism” and “corneal astigmatism.” Recall: Corneal astigmatism is the difference between the two...
LOW ASTIGMATISM: Who to fit Jessica Conroy OD, FAAO Decision-making table for Low Astigmatism (Table 1)1 Table 1: LOW ASTIGMATISM Corneal Astigmatism Residual Astigmatism Type of Corneal GP to Fit <2.00D <0.50D Spherical <2.00D ≤0.50D Front Toric ...
LOW ASTIGMATISM: Lens Design Jessica Conroy OD, FAAO Necessary for all GP fits2 Spectacle refraction Keratometry measurements Lid anatomy Lower lid position with respect to the inferior limbus Horizontal Visible Iris Diameter (HVID) Pupil size in dim and bright...
