Depends on how much dough you've got. You can get a grip cover with a built in laser beam. You can get a sight with a laser in it. You can spend very little dough and get a cheap, universal laser sight that will attached to the front of the trigger guard.
Ultra - low profile Glock Rear Sight Laser from LaserLyte. PRICED RIGHT! Bright red Laser for lightning-fast target acquisition, in a barely there package! NO unwieldy bulk, NO need to replace your existing grips or holster.
Obviously for Glock, not Taurus- but that's the idea. Find something like this for your rear sight and you are in like Flynn.