No, the eye cannot focus properly without a lens. To restore focusing power after cataract surgery, cataract glasses, a contact lens or an intraocular lens must be substituted. Unlike contact lenses which must be removed daily or periodically for cleaning, an intraocular lens implant is permanent. And, unlike cataract glasses which magnify images, an IOL produces a normally-sized and shaped image on the retina, replacing the focusing power of the natural lens more closely than either cataract glasses or contact lenses. Today's implants are quite safe.
Complications associated with the implantation of the lens itself are unlikely.
Intraocular lenses must pass a thorough approval process before they can be widely used. Most important, the benefit of an IOL outweighs the small added risk of its implantation . With any surgery complications can occur. There is always a possibility of hemorrhage, infection, or vision loss during eye surgery. Your ophthalmologist will discuss potential complications with you.