I am not aware of your exact condition of power level of your sight and your age but I remember I had similar eye irritations when I first switched to LCD/LED screen from CRT monitors and I fixed it by changing the monitor settings.

I guess, you need to check your colour agent menu in your monitor settings. Under colour agent you will have colour temperature where you will have cool/warm (and few other variations depends on your brand). If you are currently using "warm" setting then you must change to cool mode. But, cool mode will emit more blue rays which is not good for our eyes. So, you may choose between cool and warm which is cool1 or warm1 in some monitors. This helped me some 10 years back.