How the Barrett Universal II formula works - impression from a user

The following video content is an impression of how the Barrett Universal II formula works. Barrett Universal II is an unpublished formula.

[Note : The current Barrett Toric Calculator uses a unique eye model to predict the posterior corneal surface. Using Total Keratometry with the Barrett Toric Calculator would thus lead to overcompensation of posterior corneal astigmatism.

Therefore, Graham Barrett has developed three True K series of formulae: the Barrett TK Universal II for non-toric IOLs, Barrett True K with TK for post-LVC eyes and the Barrett TK Toric for toric IOLs. All three new formulas use posterior corneal surface measurements of the ZEISS IOL Master 700 instead of the eye model used by the Barrett Toric Calculator. ]