Why do we have dry eyes after reading newspaper or looking at monitor for a long time? I often close my eyes very tightly, would it cause dry eyes or retina detachment?

We have dry eyes because the frequency of blinking is less when we read or look at monitor. So either we remind ourselves to blink more, use some eyedrops or reduce the duration of reading or looking at computer monitors. Closing eyes tightly have nothing to do with dry eyes or retinal detachment.