Ever since last week Thursday I've been experiencing ease of eye strain when I just look at a computer screen, phone or tablet. Before that I never had such issue. It just takes me 10 mins continuously looking at the monitor and start to get eye strain easily and feel discomfort. I went for checkup (eg. eye sight and laser) at a medical centre and doctor don't find anything wrong. He suspect probably caused by dry eyes and given me eye drops. It's already been 1 week and the problem is not getting any better. I find it very difficult to focus and concentrate when staring at the monitor when my eye strain starts to kick in and my eyes will start to feel swollen or experience headache if I force myself to stare for long period especially with my line of work. Is this condition is due to aging? I'm almost at 40