On London buses in the 1950s there were ads of two eyes, with the words 'the eyes have it' underneath, usually either side of the bus number on the front. But what were they advertising? Photo of said advert is on my blog if it jogs any memories.

i am only 23 i wasn't around in the 50's

Maybe you remember from a past life? ;)

I've found one with Pearl Assurance on the side, and another with a British Railways advert. No help, really. Must be 50s, as the trolleybuses were withrawn in 1960-62. That one dates from 1939 and would be one of the last ones in service. Probably one of those irritating campaigns where they don't tell you the product or service - just refer to a catchphrase used in TV ads or something.

I've been asking the publishers and bus museums, and firstly the adverts on the front were usually independent from those on the side, so you could have ten eyes buses with each having a different ad on the side.
But the museum just emailed me with what you could call a definitive answer, they were advertising themselves!
There is also one with arrows saying 'see and be seen' which I wondered may be for road safety, and another with a man and woman with a target on the back of their head.
All being cryptic, they appeared to be part of a series advertising that if you put your ad on the front of a trolleybus it would be seen. Probably also a way of using unsold space.
A final PS is The magazine Picture Post had an almost identical pair of blue eyes, but did say what they were for, though this may have inspired the other ones.

So I think our answer is they are part of a series advertising the benefits of advertising on the front of trolleybuses.

I've also been told they were used when there was no real advertising being used there, and they just filled the spaces until someone else used them. I suppose at the time it made sense but looking back almost 50 years later is highly confusing!

Thank you. I've often wondered what these adverts advertised.
Meanwhile, does anyone remember the similar Eyes that advertised the musical "Cats". LT buses had two cats' eyes on the front, the pupils of which were made from the silhouette of a dancing lady. A very clever design.
Were there any more examples of Eyes on LT buses like the famous "Picture Post" "Every Wednesday" Eyes of the 1940s?