What a beautiful lens! What a unique story.

On Facebook the United States Lighthouse Society page shared a photo of the Brittany (Bretagne), France St. Mathieu lighthouse lens. It was borrowed from the  Bretagne Phare St-Mathieu Facebook page.

In French the page says:

La saison démarre bien, j’ai déjà accueillit beaucoup de monde. Et qui dit nouvelle saison , dit “Nuit du Phare”. La première nuit de cette année aura lieu lundi 5 mai à partir de 21h30. Toutes les 1/2h. un groupe de 20 personnes pourra venir admirer la mer d’Iroise et ses phares à partir du chemin de ronde. Visite uniquement sur réservation au 0298890017 ou 0686310347.

which roughly translates (with the help of Google Translate) into:

The season started well, I’ve received many. And who says new season, called “Night Lighthouse”. he first night of this year will be held Monday, May 5 from 21:30. Every 1/2h. a group of 20 people can come and admire the Iroise (sea) and headlands from the walkway. Visiting reservation at 0298890017 or 0686310347

Now what is the unique story? The United States Lighthouse Society Facebook page said:

Saint Mathieu Lens. Note: the small square lens panel in the lower front of this lens is an aircraft lens that takes part of the light upward at a 45 degree angle so that planes can use lighthouses in France to locate their position.

That is the first time in my life I have ever heard of a lighthouse lens being used for aircraft navigation. Yes, if the aircraft were low enough, then I am sure any lighthouse lamp would be visible, but to redirect the beam at a forty-five degree angle (45º) upwards is unique.

Does anyone know of any others?