I ride out a lot with someone who's horse, which was kicked in the eye when out in the field. It had to be removed. The small things, like standing on the side he can see and when you're grooming on her blind side, remind her your there by talking and praising her. Build up your trust and get to know what she is most likely to spook at. Just make sure you ride confidently. The horse who had his eye out now gets very agitated at the smallest things because his rider is quite nervous. Ride purposefully and condfidently when going out and stay to walk if you can! If she spooks or frights at something, ride past it again.

If it is her left eye, then it should be fine, as long as she is comfortable in the surroundings, if it is the eye that is on the inside of the road then i wouldn't advise it personally. If she is jumpy, then you might be able to help her out by taking her out in hand, to get her used to the road and traffic and understand that you are still there for her, and that nothing will hurt her, once you have regained her confidence she should be fine (: I think it may be a case of her being a little bothered by the fact that she simply cant see so well as she could before, and it might be making her nervous.

Remember, although she has lost sight in one eye, she still has her hearing and her other eye working fully well (assumably), Her other senses will compensate for the loss of sight in her eye, and as long as she given time and space to adapt, i can;t see any reason why you shouldn;t ride her out.

(: Hope i helped xo