[marisa-chan (OP)]

i have heard many reasons why but i don't know if any of them are true..


first explaination-- in ancient times there were many sandstorms in the east so people with naturally smaller eyes survived and passed on the gene for small eyes etc.


second explaination- the sun rises in the east so they start squinting their eues before everyone else.... They were the first people that had to deal with the sun and out of curiosity looked towards it which forever made there eyes small because the sun is so bright. (i somehow doubt this one)


third explaination- (joke one) Asian people's eyes have evolved to be slitty over time because they spend so much of their time training as ninjas. Spending a lot of time with narrowed eyes meant that the skin around the eyes (including eyelids) didn't need to grow so much. It's the same effect as when muscles gradually waste away if they are not used - the body will only produce as much tissue as needed.



is there an actual explaination? or is it just some strange variation thing that people from the east developed?

[blakestyger]

The feature to which you refer is the epicanthic fold which is a characteristic of the Mongol races. It arises where the eyelid muscles are weaker than in those who do not have it.

The hypothesis is that the epicanthic fold protects the eyes from UV light in those environments where sunlight is harshly reflected - such as permanent snow, tall yellow grasses of the savannah etc.