You might be suffering from what we call computer vision syndrome, an occupational disorder caused by excessive screen usage. To address this problem, start practicing 20-20-20 rule (you can look it up on the internet), give periodic rest to your eyes, use a larger screen where possible, keep the screen at least 2 feet away from your eyes, engage in non-screen activities apart from the necessary work time. You may use CMC 0.5% eye drops every 2-3 hourly while working, for lubrication of your eyes. These will be available over the counter at any medical store. Be conscious about your blink rate (we tend to blink less during screen usage).