hi. one has to put in mind the timing everyday is specific on the night after work .what happens is when we are working on long hours on the computer our eyes tend to dry out and leads to symptoms of dryness . after 20 minute of work on laptop computer ,give yourself a break of 20 seconds and look at a distance object 20 feet away ,what blinking after 20 minutes does is reform the try film and looking far relaxes your eye muscles . a visit to an ophthalmologist cannot be undermined ,so please show an eye specialist dr MARWAH