When conjunctival impingement occurs, showing excessive blanching; order a lens with a flatter peripheral edge zone. The 15.8mm lens offers two options (1 Flat, 2 Flat), and the 18.0mm lens only one option (1 Flat). When a 2 Flat option is ordered, lens sag depth value must be increased by 100 microns to compensate for lost apical sag depth value.