Contact lenses

[ThickSkin]

Situation that occured last week:

I was officiating a varsity contest between two rivals. I noticed about midway through the second quarter one of the players had on a pair of contacts that, had he been hit and knocked unconscious, would have prevented anyone from seeing his pupils/eyes.

I know that players are not allowed to wear shields for this very reason and I have been unsuccessul in finding it in the rule or case book.

Any and all help would be appreciated.