Redness of the eye in height altitude?

Dryness: Likely your eyes are dry if outdoors in high altitude because of low humidity. The redness is due to the irritation provoked by the low humidity environment. Try artificial tear drops to soothe the ocular surface and to help them recovery faster. Remember to wear sunglasses outside too, as there tends to be more uv associated ocular irritation, in addition to the protective effects of screening.