Is it possible to have a defective implant with cataract removal?

Extremely rare: Although there is such a thing as a defective implant, with modern quality controls that is an extremely rare problem when implants are obtained from reputable manufacturers. It is much more common for the power of the implant to not exactly match the calculated power needed to minimize glasses use after surgery, and sometimes the difference is enough to warrant replacement of the implant.

Implant: IOL: Depending on other risk factors (length of eye: if very short; history of other eye, h/o trauma, diabetes, on aspirin, general health, etc) cataract surgery is generally very safe and recommended if vision