“…[5,6] These designs include two commonly used methods; Prism-ballasted design that involve interaction primarily from the upper lid and Non prism-ballasted design which both eyelids play an active role in stabilization. [6,7] The stabilization methods used in some of the toric soft contact lenses are: Prism ballast (Pure Vision Toric), Precision balance (Air optix for astigmatism), Prism ballast (Proclear Toric), Optimized Ballast Design or Equi ballast design or Horizontal iso-thickness design (Biofinity Toric), Accelerated stabilization design (ASD) (Acuvue Advance for Astigmatism). [8] The first Four lenses have prism stabilized designs, two of which (Air Optix for Astigmatism (Alcon) and Biofinity Toric (CooperVision)) incorporate modifications to avoid interaction with the bottom lid.…”