Teenagers spend too much time on computer games,what effect does this have on them?why?

Well, computer games, though entertaining and exiting, do produce a significant impact on the growth of youth people. They have become a social issue which is highly debated, and their downsides are apparent.
First of all, computer games can be a waste of time. There is no denying that those playing games on a computer have to spend lots of time on them, which is time-consuming. Consequently, their academic performance is affected, causing possible failures in exams. Even those who are addicted to games tend to drop schools.
Second of all, watching the screen of a computer can damage people's eyesight. It has been widely reported that the citizens' eyesight is getting increasingly poor, due to more frequent use of computers. Besides, games often draw children's too much attention, making them forget to rest, which is harmful to their eyes.
Third of all, many games, in order to be entertaining for adults, contain violent or obscene contents. So, the viewers, who unfortunately happened to be children, would negatively instructed and badly influenced. Some social investigations have indicated that violent games are in relation to the rise of adolescent delinquency.
In a nutshell, computer games indeed pose a great threat to our younger generation. But they also have some benefits that we shouldn't ignore. It is universally accepted that online games, with a growing popularity, have become a rising industry, creating a great amount of fortune for our society. What's more, computer games are surely a good and convenient way of relaxation, which other kinds of entertainments can hardly be.
In my opinion, we should develop a correct way of dealing with computer games, and only when their merits are enhanced and their demerits are discarded, can we benefit the most from it.