You may be able to get some clear UV film from somewhere and stick that to the lens.

thats what i was trying to get at too. it just needs something to absorb the UV for it... sacrificial lamb if you like

as i said plexus is the go...it i used to clean and protect aircraft windows......and it works..

just get headlight protectors... kill 2 birds with one stone then...

AFAIK It is caused by the heating/cooling effect, the heat of the globe with the immediate cooling of the lens from the rain, causes the formation of a film. This film consists of the foriegn elements (crap) in the rain mixture.

This is why you will find the majority of ppl with lens protectors dont have the yellowing effect, as it creates a seal, which means the physical lens does not get wet.

And no GTBob I didnt get it from my beloved Gregory's manual.....

So what your saying is that the lens get sunburnt?

Not specifically knocking MrGregory's books but they do lack a lot of information, same as Ellery's and I have found a lot of misinformation in these publications over many years as a MECHANICAL ENGINEER

I am not questioning your abilities, or the fact that Ford manuals are the better option, or that gregory's/ellery's manuals arent underinforming, but they do give the simple man some idea of where to begin.

Did someone say Plexus????

Finally.
Someone who is talking from experience.
A product worthy of mentioning.
A product that really works.
Well said.

Plexus is a plastic polish and is used by amongst many others, NASA and the US Air Force, .......just to mention a few.

This is really serious stuff and it's so easy to use.

Either before your lenses go yellow or after having fixed and removed the yellow from them, just spray it on once a week and wipe with a clean soft cloth.
It penetrates and lifts even the most difficult stain without damaging the fragile surface of the plastic.

It is also anti-static. It repels the dust and dirt normally attracted to plastic. It leaves an invisible, micro-thin protective layer, sealing the porus surface of the plastic, making it more resistant to dirt, dust and other contaminants.

Regular use will help prevent hazing, yellowing and oxidation which diminishes the plastic's lustre, strength and appearance.
Water beads and slides right off the vehicle when it rains!
You can use it on any clear or coloured plastic surface, convertible windows, bug guards, window tint films, fibreglass boats & RV's, big screen TV's, LCD computer screens, helmets, goggles and fairings.

It is amazing.

But also remember to make sure that the material used in the manufacturing of your Halogen bulb is of UV stop Quartz.
Since Halogen bulbs emit lots and lots of UV.
HID bulbs emit a fraction of what Halogen bulb do. In most case the UV emitted from HID bulbs is negligent.
That is why OEM HID bulbs can now openly recommend use of their bulbs with Plastic Lenses.

I am sure that “iam deathâ€￾ can tell everyone where to find it.

Thanks “iam deathâ€￾ .