I'm not sure if anyone has posted similar. It's a known fact that the headlights on Lexus cars, the older ones lol, go let's say murky. Green looking etc. I've had to replace the passenger side headlight last year as it was letting in water. The replacement even though 2nd hand looks brand new and put the drivers side headlight to shame.
Anyway today I spent just under an hour renovating mine. I used the Autoglym headlight renovation kit. It's actually very good but I think it could use a more course paper as 1st pass.
When I got my is250 the headlights had a black film on them with loads of holes to let the light out. Had them taken off but over time the residue of them kind of embedded into the plastic housing and no amount of washing could remove.
The 1st photo clearly shows what I mean. The 2nd photo is end result. Not mint as there are a myriad of internal scratch looking marks.