One hypothesis as to why epicanthic folds came about involves the climates in which populations expressing them arose. Sunlight reflects more intensely off light colored surfaces, such as those prevalent in snowy regions or savannah and deserts, and the theory is that an epicanthic fold in such an environment would expose a narrower section of the eye to incoming light, reducing the amount of light entering the eye. The trait may also be useful against strong winds.[1]. With regards to the Khoisan in Africa, it is likely that the epicanthic fold was acquired for analogous reasons. Specifically, in the vast dry grasslands of the Savannah regions, the yellow grasses also reflect and intensify sunlight. Additionally, analogous conditions are present in the case of the little mentioned epicanthic folds of Saharan groups such as the Dinka or Nuer of Sudan (Hassan, 1962) who live in environments in which sunlight reflects off of the light colored sands of the desert.