Some of us sit for prolonged hours in front of a computer screen. There is no doubt that such exposure to screen light harms the eyes. In my personal efforts to protect my eyesight as a programmer, I have found that reducing screen brightness can be very helpful. It makes the whole experience mroe comfortable and reduses eye strain.
There is a number of freely available programs that let you adjust screen brightness. F.lux is on of them. In addition to adjusting scren brightness, it makes the color of your computer's display adapt to the time of day, warm at night and like sunlight during the day.
To reduce PC dispaly brightness:
a. Download and install f.lux software on your PC / laptop for free.
b. Use alt + pageup to increase brightness and alt + pagedown to reduce it.