"Slanty eyes" Incorrect?
Leading Quebec politician Andre Boisclair is in trouble because he said that a lot of the students at Harvard had "les yeux brides" - slanting eyes. Apparently French-speakers had no problems with that expression but Anglophone Canadians have been huffing and puffing about it.
If you can describe someone by such a physical characteristic as their skin-color, why can you not describe them by their eye shape? It is after all their eye-shape rather than their skin color that differentiates Asians from Caucasians.
The Duke of Edinburgh once used the expression "slitty eyes" to refer to Asians and that produced a bit of tutt-tutting too.