This website would allow you to determine the farthest disctance you can see from anywhere on earth. Simply enter your GPS location and your eyesight (20/20, 20/400, etc.) in the appropriate fields and press the "calculate" button. Within a few seconds, a printable screen will appear with a map of the chosen area showing a line going all the way around your location, which is the percieved horizon that can be seen from your chosen spot. In mountainous areas, the line would be very zig-zaggy, but in Nebraska or on the open ocean it would be a circle with your location in the center. The map would also highlight points (such as tall buildings, mountains, etc.) whose tops are visible but whose bases would be too far away to see.-- Rubi, Dec 05 2003 Lunar Eye Chart http://www.halfbake...Lunar_20Eye_20Chart [phundug, Oct 04 2004] Mt. Diablo http://www.interakt.../LUnE/MtDiablo.htmlAs [luecke] pointed out - ">On a clear day< [emphasis added], from it's summit you can see more of the surface of the earth than from any mountain except Mt. Kilamanjaro in Africa" [Klaatu, Oct 04 2004, last modified Oct 21 2004] Some people don't know their eyesight offhand. It might be wise to include an eye test on this computer site. Or, if you are out in the mountains of Nebraska, you could use the Lunar Eye Chart :) <see link>-- phundug, Dec 05 2003 Will it take the weather conditions into account? I could have 500/20 vision and still not see any more than 20 feet into a good fog.-- luecke, Dec 05 2003 "the farthest distance you can see from anywhere on earth" - that would be the stars, and measured in light years - not what you had in mind, I believe.-- DrCurry, Dec 05 2003 If you are in the panhandle of Texas you would have quite a clear circle arround you also. If cows had GPS trackers, it could accomodate for them too. There would be FLOCKS - LEGIONS of little black dots on your display.-- Letsbuildafort, Dec 05 2003 Mind if I ask why anyone would want this?-- phoenix, Dec 05 2003 or how this idea takes into account stuff between the viewer and the horizon, and local topology ?-- neilp, Dec 05 2003 The horizon never gets any closer, I tried to get there for years and years.-- ato_de, Dec 05 2003 Two places on earth where you can see more of earth's surface than anywhere else on the planet. <link>-- Klaatu, Dec 05 2003 [tsuka] This depends on whether or not the universe is infinite, and whether you are in a funhouse.-- Worldgineer, Dec 05 2003 great question, tsuka! that could have been me speaking :)-- po, Dec 05 2003 How lovely that a page about this place with incredible views has virtually no pictures.-- waugsqueke, Dec 05 2003 random, halfbakery