We describe the interaction of the neodymium: yttrium aluminum garnet (Nd:YAG) laser energy with intraocular lenses using the laser in the Q-switched mode. Using this method, it is possible to treat opacities that eventually might occur at the level of the visual axis on the optic faces of polymethylmethacrylate intraocular lenses (IOLs) if safety parameters (perfect focusing, use of additional lenses, and slight and continuous movement of the focal point of the laser) are followed. However, it is not possible to treat the silicone IOLs with the Nd:YAG laser because the threshold values for damage to the IOL are lower than the energy values required for destroying the capsular opacities on the optic axis.