It's not only the eyes, but the belly near the sexual organ (male or female) that turns red due to the licking. Here in the U.S., we use a product called
Eye Envy which is applied to the reddish areas and works very well and is tolerated well by the dog (Zuchon… Shih Tzu/ Bichon Frisse cross)… Seen here:
http://astore.amazon.com/alshtz-20/detail/B001RIDZ1A
We've used it for over a year and although somewhat expensive it works… Perhaps it's available in the U.K.