Glad to hear everything is going well for you in Colorado. You are correct; radial keratotomy (""RK"") can and did cause problems for one of the Everest climbers, Beck Weathers, that contributed to his demise in the terrible '96 season chronicled by John Krakauer's ""Into Thin Air"". Weathers' visual problems, along with other major errors in judgment, and brutally severe weather, led to numerous casualties that year on the mountain. Since then, intelligent climbers and trekkers have been wise to inquire about their own risk factors, and ask whether LASIK is different than RK in regard to altitude-related risk.
What was not well reported at the time was that Weathers had undertaken RK surgery something like ONE WEEK before flying to Kathmandu and then Everest base camp. Apparently, he did not inform his eye surgeon about the imminent plans to climb Everest, nor did he advise his mountain guides that he had just received RK surgery. The short interval from surgery to altitude challenge certainly made things far worse than they might have been for him otherwise.
Thankfully, RK surgery is now obsolete, having been replaced by the much more accurate and stable methods of laser vision correction (LASIK nd PRK). The radial, deep corneal incisions of RK have been eliminated in favor of very superficial laser sculpting as in the latter procedures.
You may also find solace in knowing that the partial pressure of oxygen at 29,000 feet is much lower than the partial pressure on either Anconagua (I think peaking at 22,500) or in the Mexican volcanoes which you say are in the 18,000+ range.
The other good news is that LASIK does not pose the same altitude hazard as RK, even shortly after surgery. A friend of mine did a LASIK fellowship in Argentina in '97, and his wife had LASIK there just before he finished. Two weeks later they went trekking in the Cordilliera Blanca, I think, climbing to above 16,000 ft. He brought along some testing equipment, measured her vision and a bunch of other parameters, and actually wrote this up in one of the ophthalmology journals. She did fine; had no problems, not even any temporary blurring; she retained great vision, and they are still (happily!) married.
Have a great time, stay healthy, hike well and send us a postcard when you can! And keep enjoying that great vision.
NOTE: Kelly had LASIK in August, '00. Her referring optometrist informed me of that her vision after surgery was 20/15 in one eye and 20/20 in the other. She was, to say the least, extremely pleased with her vision, and that was before the correspondence noted above. - DW