A Person who spends all his free time watching T.V may cause several problems......automatically he will be addicted.....once he get addicted.....
It decreases the concentration of the person and leads to distraction while studying.
It may leads to eye problems.....

how can we deal with that addicted person to get rid of it ?
He / She should try his best to to reduce that habit.Because in this modern generation,its really important to mingle with family,friends and nature.He/She could utilise the environment and play some healthy games too.It will affect his/her health which is really important for us.And if he/she is a school going student it is surely going to reflect on studies.It may also affect him/her mentally. Hope it helps and pls mark it as the best answer. :-)