It’s a very difficult situation for you travelsafar as she is your friend. Have you been a passenger with her being the driver before - has she always been like this or is it a recent development?
What did your other friends feel about her driving ability?
OP say report her, but who to, exactly? The DVLA? I think they would require more than a passenger expressing concerns? Perhaps there are family members (if you are close enough to them) who you could raise your concerns with, or, as others say, if you feel you could, raise it with your friend herself? (Although I appreciate this could be difficult for you and might not be the route you’d wish to take).
Maybe you could tackle it in a more round about way, later - not when you’ve just been a passenger in her car - but more generally around eyesight issues - blurred vision/cateract conversations, emphasising how important it is to have regular eye checks and have cataracts dealt with, and how doing so improves vision, perhaps? (This conversation might work better with several of you discussing it rather than just you and your friend? Hard to say really, not knowing your friends personality and how she would react to such conversations).
I hope you can come to a satisfactory resolution soon.