It seems that you have to live with computer for quite a long time each day right? Maybe this is due to work requirements or something. Anyway, as far as I know, your assumption is right, at least to some extent, because the computer always gives out some harmful lights and we could simply do nothing about it. In the long run, your vision would be affected and you will face some relevant problems. However, if you pay more attention to your eyes and refresh them from time to time, things could be better.
Well, of course, it can cause permanent damage to your eyes, if your watch computer too much, for it can lead to eye strain, and then can cause many eye diseases. Generally speaking, if you have got eye strains, it can lead to many long term effects. For example, it can put stress on the eye muscles and the facial and scalp muscles, causing pain and headache. And what is worse, it can lead to making your vision become worse. And finally, you have to wear glasses. In a long term, eye strains can make your eyes become dry and lead to dry eyes, and watery eyes. So you should not watch computer in a long time. And just keeping your eyes be in a good rest is very essential.
Yes, the heavy computer use will cause the permanent damage for the eyes because it will cause the total damage of the visual nerves. When you use the computers for a long time with no rest, the eye nerves will be intense and you will get the tiredness. In long time, your eye nerves will be broken. That is the main reason for the eye damages.
No, it would not cause that, but it can cause computer vision syndrome (CVS). It is a temporary eye condition for those people who use computer for a prolonged period. The main symptoms of CVS are blurred vision, headache and fatigue of eye muscle. And the long-term influence of it is causing eye problems, such as myopia. Hence, you can wear computer glasses that are prescription lenses to relieve computer vision syndrome. At the same time, you should take frequent breaks when you are sitting in front of computer screen during the day.