Reason for that though: it's easier to see blood and other fluids on a bland / white wall. Since fluids are a common way for infectious diseases to spread, they need to be cleaned thoroughly and completely.
Source: wife is a nurse in the ER.
Source: wife is a nurse in the ER.
However, those lights are usually handheld and small. Expecting cleaning staff to cover 100% of all walls each time they cleaned it (which is multiple times a day) is prone to failure.
Plus those lights work best when the room is dark. Which means you could only clean it at night.
And some rooms have multiple patients, so now the cleaner people will need to work around them / have them be OK with the room being dark for a while. This can work, but again not every patient will be comfortable with a "crime scene investigation" happening while they recover.
Think viable transmission vectors for those diseases.
I don't know what hospitals you're going to but the ones in the US don't qualify that statement. Would I say they're filthy? No, but they certainly don't look like they're cleaned often, thoroughly, or completely.
Edit: there was even one room where I put on rubber gloves and used the disinfectant wipes from the janitor’s cart to clean dried blood from my IV pole and the bed rails.
Oww, come on, that is simply not true, in the last - say - 100 years in Italy (post WW1 emergencies).
So, either your friend is very, very old, or she is making it up for the benefit of folklore.
Until the '60's or maybe early '70's syringes and needles were not "use once and throwaway" but of course they were washed after every use and sterilized before a new use.