I came across this while studying Mishna Yomi (Shviis 5:6).  Kehati quotes the Rambam on this mishna:
אמר הכתוב: "לפני עור לא תתן מכשול" -- רוצה לומר: מי שסגרה עיניו התאווה ויצר הרע, לא תעזור אותו להוסיף בעוורונו

[My translation]
The Torah states: "Do not put a stumbling block before the blind"-- meaning: regarding one who has been blinded by lust and the yetzer hara, you should not provide assistance to further his "blindness"

It struck me to have the words of the Rambam make taava/yetzer hara the causers of blindness.  I can know what's right, but still, what I do is different, sometimes out of control.

This helped me; I hope it helps someone else.