To begin with, active 3D glasses are uncomfortable, cumbersome, and heavy — up to 2.2 ounces (62 grams) in the case of Sony’s active glasses, compared to 0.5 ounces (14 grams) for passive glasses. Active glasses and TV sets also provide incredibly poor viewing angles: unless you are sitting within a few degrees of center and with almost zero horizontal (head) tilt, the contrast, brightness, and image quality plummet. Passive glasses (and TVs), in comparison, are excellent with any head tilt angle, and with most realistic (greater than 30-degrees-from-center) viewing angles.

via Why you should buy a passive 3D TV | ExtremeTech.