My texts do not fit uneducated tropics with poor eyesight

All of my texts and videos presuppose a starting level roughly given by having learned my thinking course http://quickerlearning.blogspot.fi . The thinking course presupposes a good eyesight, a good ability to understand what one sees and observe landscapes with an understanding of the structures in them. As far as I know most human races have these basic skills of looking but those from black Africa do not have them but look with social eye like one observes the shapes of trees and bushes in darkness, thinking if they are maybe like monsters. Also heavy food on a hot day is not good for understanding what one sees, neither are air conditioned (cooled) indoors as an environment where one uses one's eyes most.