how much is too much?

I am currently with computer access at most 1 hour per day due to work and curso.mas the weekend get a little more on your 4 to 5 hours or more. is very rare to send messages from my cell phone almost no use. not they have a specific time for each activity. yes, it is necessary to set a schedule so the future does not become an addiction. can impair vision, posture, can cause back pain, and also hamper their studies.