PH
Blinking isn't completely automatic at a fixed rate. Research has found that blink frequency can decrease substantially during visually demanding activities such as reading or working at a computer.
Fewer blinks can allow the tear film covering the eyes to evaporate more quickly. This contributes to the dry or tired feeling people sometimes experience after prolonged screen use. The same person can have very different blinking patterns depending on what they're doing.
Concentration can quietly change something the body normally does automatically.
© American Academy of Ophthalmology