The paper reviews the most frequent problems with eyes and vision that hikers may encounter at high altitudes. Particular attention is drawn to chronic eye diseases, as the severity of the disease may be augmented by high altitude. Most altitude-induced problems with vision, such as refraction, snow blindness and some forms of high altitude retinopathy, are reversible, but some, such as retinal haemorrhage in the macula, may also have permanent consequences. The article concludes that no chronic eye disease is considered a contraindication for high altitude hiking. However, in patients with chronic herpetic eye disease or severe myopia, as well as those who have recently undergone eye surgery, high altitude exposure may reversibly enhance the severity of their eye problems.