How can i prevent eye redness?

Prevention?: The eye's normal response to anything that irritates it is to become red ;/or to tear ;/or to make more mucous. Trying to protect the ocular surface with glasses, sunglasses, broad brimmed hat, artificial teardrop applications, to blink more, to rest them when tired, to eliminate environmental irritants, and to use antihistamine drops when itchy may all help. But to prevent redness is not likely.