U can reduce brightness of ur computer and can use antiglare screen guard... Also antiglare glasses if needed as it is not possible to take break sometimes during urgent works online.  Increase ur blink rate and use artificial tear drops whenever u need as many times a day. 

First step is to cut down screen hours ,if it's not possible than give intermittent rest to your eyes by following 20-20-20 rule.its after 20 mins of working close your eyes for 20 seconds and look at a distance of 20 meters.Use any lubricant eye drop from reputed company . Improve your sitting position, adjust screen brightness, take plenty of fluids, good nutritive diet.Daily yoga and relaxation exercises.

You can use any lubricant eye drop for long term, there are no side effects. Take frequent breaks during screen work.

You can use any over the counter available lubricating drops...Refresh as u said You can use as many times , as per your need...2/3/4 times per day Just make sure , you use a new bottle after 30 days, if u r not using regularly ..write date of opening on bottle