One of the Physiological effects of watching TV in excessive amounts is eyestrain. It is true that there are specifications or watching TV; TV should be 5 m. away from the eye, the room should be adequately lit, TV should be place at the same height with our eyes, etc. However, these do not prevent our eyes from getting tired if we keep watching TV for a long time. Another effect is obesity, which is widely observed in people who like watching TV and eating snacks everyday (there is even a term "TV snacks" to fast food that is suitable for eating in front of the TV). TV is such a powerful machine that people cannot get away from it - it is addictive.