It depends on what type of implant you had. If you had the standard implant that is single focus (meaning you can only see clearly at distance and need reading glasses), yes you can use your laptop.
However, if you had the Crystalens, which is a multifocal implant (meaning you can see at all different distances) then it is highly recommended that you DO NOT use your laptop, or other computer and absolutely no reading. This is required to allow the lens to seat properly in the lens capsule. For more information, you should read my hub on cataract surgery.