f.lux changes the Color temperature of my mac screen in the evening, so that the blue light from the screen is removed, and instead a nice warm set of colors are emitted from the screen. This drastically reduced the strain that I felt on my screen at night. It felt weird, the first 3 or 4 days, when my screen colors changed in the evening. But then soon enough, I even stopped realizing when f.lux changed the colors. It would only be a passerby, who would look at my screen, and wonder: Hey what happened to your screen?
Over the last few months, I have recommended this app to many friends. One of whom used to get a headache by evening working on the computer, and had resigned to the fact that such is life. After trying out f.lux, his incidences of headaches have drastically reduced!
As the f.lux website says: “f.lux makes your computer screen look like the room you’re in, all the time. When the sun sets, it makes your computer look like your indoor lights. In the morning, it makes things look like sunlight again.”
I would recommend you to try (please note, I am not a doctor!). f.lux sits happily in your menu bar, and you can toggle it temporarily off (for an hour) when you feel the need to switch back to normal color mode, say for doing some photoshop or color editing, etc. f.lux is also available for Windows, and I think similar apps are now available for tablets & phones too.
Do try out these apps.