For those of you playing on a newer PC with a more recent graphics card I've got excellent news. You might be able to enjoy a little feature called TressFX which will fight bad hair days. Check out these lovely comparison screenshots:
(first image shows the regular version, the second is with TressFX)
Click to enlargen.
And more TressFX screenshots:
Wow! Lara's hair has never looked so much like... Actual hair! 
So shiny that one might need sunglasses. 
Just looks so realistic this game does! Cannot wait to get it 
That's quite something, isn't it! It makes the scene appear much more natural overall.
i concur. the hair with this feature looks amazing. it moves properly and flows over objects too.
one thing a bit wrong for the game (as mentioned earlier) is that the hair is shiny - like she's just walked out of a salon. but instead the rest of her is covered in muck!
