Currently available are 11 monofocal toric IOL models, five of which are FDA approved (Table 4.3), and four multifocal toric IOL models, one of which is FDA approved (Table 4.4). There are a variety of IOL biomaterials including silicone (Staar toric), hydrophobic acrylic (AcrySof toric), hydrophilic acrylic (Rayner T-flex) and polymethyl methacrylate (PMMA) components (Hoya iSert toric). The type of lens material has been shown to influence the postoperative rotational stability of the lens. After implantation of the IOL, it is thought that the anterior and posterior capsules fuse with the IOL, creating adhesions that prevent rotation of the IOL [35, 36]. Additionally, different IOL materials may have differing affinities to proteins in the capsular bag. Fibronectin, in particular, has been reported to play a significant part in the formation of IOL-capsular bag adhesions [37]. Acrylic IOLs explanted from human autopsy eyes have been shown to contain significantly more fibronectin than silicone or PMMA IOLs, suggesting that acrylic lenses may form stronger adhesions with the capsule [37]. Lombardo et al. also found that the highest adhesive properties were demonstrated by hydrophobic acrylic IOLs, followed by hydrophilic acrylic, PMMA, and lastly silicone IOLs [35].