According to reports on Álvarez’s Facebook page, the 54-year-old summited the 29,035 foot Mt. Everest on Sunday, but suffered retinal damage in the thin air.

Blinded, Álvarez was helped on the descent by fellow Mexicans Jorge Antonio Salazar and Jorge Hermosillo, who abandoned their own Everest summit attempts to rescue their countryman.

This morning, Luis Álvarez’ son, José Manuel Álvarez, posted encouraging news on his father’s Facebook page: “I talked to my dad in the base camp… He still does not see. But the damage is reversible and we expect the recovery of [his] eyes during the course of these days.”