Throw it away.
Now.
I don't know how much harm the mold and black dots do, but get rid of it.
Like,
Nao.
EDIT: Found this, dunno how helpful it might actually be, but it's a start.
http://whatscookingamerica.net/Q-A/Mold.htm
Like said above: Throw it away. ASAP.
Imma attempt to clean it first using heavy duty crap before I toss it (it is a rather nice water bottle

Unless you've already developed an allergy, then normally not.
(if this sounds contradictory to the advice to throw the bottle away: You can get other stuff from molds; most prominently for people who are not already seriously ill: liver cancer)
Maybe I have an allergy to it then?

Eye strain can cause headaches. Get an eye test and tell the optician about the headaches. They'll put the eyedrops in that relax the muscles. I had 20/20 in every cursory test and after the drops i was half blind.
I moved my desk under a window, made an effort to look out the window to shift my focal length and got a pair of reading glasses that I hardly ever use. No more evening headaches after whole days reading and on the laptop.
I already wear contacts, and I do make an effort to look out of my window every now and again to look at things in the distance, also the view is really pretty.
And I've already tried going days without wearing contacts to see if that would help, it didn't, so I'm thinking it isn't the cause.
Mold can be nasty crap. Minimize contact. If you are for some reason unreasonably attached to a plastic water bottle, you can dump an 80% water 20% bleach mixture in it and wash the bejeesus out of it. Then rinse the bejeesus out of it. Better be a darned good water bottle tho!![]()
It is rather nice... I'll try my best to murder the mold. If that fails it gets tossed.
Hopefully no longer using that water bottle will clear up these headaches. If not, allergy meds. If that fails, doctor.
Thanks guys for the help and ideas!