The only way a computer will affect your eye is if you fall face first on a motherboard. I think what you mean is if a computer SCREEN will have a negative effect on your vision. The answer is - it depends. If you are doing a lot of stuff on the computer you might suffer from eye strain. This is most predominant on older screens which are set to a low resolution or a low refresh frequency (less than 60Hz). Most modern computers are set to a high resolution and most use low power LCD or plasma screens. Older computers that used CRT (cathode-ray tube) technology were notorious for giving people eye strain because of the electromagnetic radiation leak that was unavoidable with that technology. Because of technical advancements, I would not be too worried about it.