Having, in a former life, worked as a TV repair technician, and having personally administered the violent release of CRT vacuum on numerous occasions, I can testify that most CRTs have a front glass thickness ~1/2" - 3/4" thick, depending on the size of the CRT.

Hence my attempt at doing this resulted in my using a pinhole camera in front of the CRT, where the pinhole size was about the same as the phosphor pixels on the CRT. Of course, a glass camera lens also would work, perhaps with a faster exposure time, but you may have issues with focus at the edge, since most glass CRTs are curved, if you used a wide angle lens and a close-up distance to the TV. You probably would have better results with a longer lens further away from the screen, getting a flatter field.