The IOL of AddOn® 1stQ (Fig. 11.1) consists of a square basic geometry and a 6.0 mm optics. The square geometry prevents an iris capture. The hydrophilic acrylic IOL has a convex-concave optical design, which has an edge in all four quadrants of the optic rear surface, which ensures a steady distance to the base lens. The distance from the base lens is on average 0.64 mm [1]. This important design feature prevents a touch of both intraocular lenses, which might change the refraction such as diminishing the toric effect (Figs. 11.2, 11.3, and 11.4). On the other hand a stable refraction and refractive predictability is guaranteed (Fig. 11.5).

The main feature of AddOn® IOL’s is the four diamond-shaped haptics on the four corners of the square basic shape (Fig. 11.1). They provide a neutral adaptation of the IOL to the anatomical conditions of the ciliary sulcus by absorbing forces acting from the outside on the haptics without transferring these to a decentering or rotational component. This feature ensures a high stability in the ciliary sulcus and is especially important for toric and multifocal AddOn® intraocular lenses.

The main indications of AddOn® IOL are: