Some other problems should be taken into account also. Too much bright light reflecting off of white pages will fatigue your eyes, give you a headache and cut your concentration. Not enough light can have the same effect. The contrast between the dark room and the white pages is bad for your eyes. Extreme cold inhibits memory, but it's best to keep the room on the cool side.
Slight discomfort seems to help the mind concentrate.
Is there enough fresh air in the room. Your poor brain is starved for oxygen in a stuffy room. Not having enough air will dull your mind and put you to sleep. Your mind is lodged in a body which must be considered in the study program. Sufficient light, heat and fresh air are all necessary.