Most computer uses would suffer different level of eye discomfort from computer work. If you don't have any symptom of CVS, you don't need Computer Glasses but a pair of protective eyewear is good for your eyes to prevent potential damages.
Yes. Even though you don't have any symptoms of CVS, you will still benefit from computer glasses. Wearing computer glasses while using computer will make you feel more comfortable so that you can work on computer more effectively. If you spend a lot of time each day on a computer, you'd better get a pair of computer glasses.