It seems that there is something wrong with your eyes. So, as far as I know, eyebright is a kind of plant that is used to treat some eye problems, so in this sense, you could use it to help your eyes. But, it is not enough, which means that you still need some other efforts, such as artificial tears, or eye drops, and try to quit some bad living habits. Maybe you could mix it with your food for help.
Well, yes, eyebright can be good to treat dry eyes. as we know that eyebright is extensively used to treat different eye problems such as conjunctivitis and dry eyes, for it is rich in beta-carotene, vitamins B, C, E, caffeic acid, flavonoids, alkaloids, glycosides, volatile oils and tannins. By the way, according to some experts, eyebright supplements can treat eye strain, and eye irritation. Its eyewash is often recommended for cataracts and bloodshot eyes. so you can just have a try.