How can i prevent blindness from using computer?

After i read this article about how one can get blind from excessive computer use i became scared. Does anyone know i can prevent getting glaucoma while using my computer about 6 hours daily. I work on computer so i can not forgo my job. The article is at a href="http://news.bbc.co.uk/2/hi/health/4008185.stm" rel="nofollow"http://news.bbc.co.uk/2/hi/health/400818…/a