Lower the in-game brightness
Reduce bloom
Reduce lens flare
Lower post-processing quality
Lower global illumination quality
Lower shadows quality
Lower volumetric fog
Lower ambient occlusion
Disable motion blur
Disable film grain
Use a matte or anti-glare monitor finish
Increase room lighting to reduce screen contrast
Adjust monitor brightness and contrast
Use a hood or anti-glare screen filter
Change camera angle to avoid direct light reflections
Close curtains or blinds to block sunlight
Avoid playing with bright light sources behind you