Madeleine's very distinctive eye pattern is discussed on this video where Kate and Gerry McCann are interviewed by Piers Morgan.
Watch from 0.35 - 1.30
PM: Madeleine had a very distinctive eye pattern, didn't she? Tell me about that, Kate, in case people see somebody they think may be Madeleine. Tell me about her eye.
KMcC: If I'm honest, we haven't put too much emphasis on her eye because I think you have to be very close to her to see it, but her eyes are slightly different colours and one of them has a brown fleck in it...emm...but you do notice particularly on photographs, but...
OK then, who produced these posters?
Why is Kate McCann wearing a badge that says, "Look into my eyes."?
But they haven't put too much emphasis on her eye!
Oh dear, Kate McCann seems to have forgotten something. Again! She doesn't appear to remember not just all of the above, but what Gerry said in an interview for Vanity Fair magazine, that was published in January 2008. I guess that is rather a long time ago! Kate McCann says she never reads what bloggers and other people on the internet have to say, but she might at least read the official interviews!
Vanity Fair January 10th 2008 (See page 5)
Although initially reluctant, the McCanns finally informed the media of Madeleine’s unique right eye—a risky revelation. Whoever had taken the child now held a universally recognizable little girl.It was a what, Gerry? A good marketing ploy! But you haven't put too much emphasis on her eye!
Gerry understood that. But, he says, the iris “is Madeleine’s only true distinctive feature. Certainly we thought it was possible that this could potentially hurt her or”—he grimaces—“her abductor might do something to her eye.… But in terms of marketing, it was a good ploy.”
Another piece of the history of this case being re-written after the all those posters, the Bryan Adams song, "Everything I do," as the theme to videos and Gerry admitting that it was a good marketing ploy!
How does that cliché go? Ah yes! You couldn't make it up! Well, it appears that Kate and Gerry McCann can!