Spherical GP Lenses – FAQ 5

Inferior Decentration?


Edge thickness, center thickness, high edge clearance, flat base curve radius.


  • Use of a lenticular (or similar design) if indicated (i.e., plus lenticular for high minus powers — typically ≥ -5D to reduce the edge thickness of a high minus edge; minus lenticular for all plus and low minus — typically ≤ -1.50D powers to increase edge thickness and help lid attachment with these thin edge designs).
  • Use of an ultrathin design.
  • Reorder with steeper peripheral curve radius and/or narrower peripheral curve width.
  • Select a base curve radius 0.50D steeper, at minimum, than current lens.
  • Use a bitoric design if corneal cylinder is ≥ 2.50D.

Useful References

GP Lens Institute



GP Lens Institute Advisory Committee members: Bruce Anderson OD, Marlane Brown OD, Carmen Castellano OD, Walter Choate OD, S. Barry Eiden OD, John Laurent OD, PhD, Derek Louie, OD, MS, Joe Shovlin OD, Frank Weinstock MD, Bruce Williams OD.