patency (plural patencies). ( 1 medicine) The degree of openness of a tube, such as a blood vessel or catheter; the relative absence of blockage. ( 2 uncountable) Obviousness; clarity.
Maximum Length: 16' with a standard cable, Up to 50' with a high quality cable. VGA is an analog signal and so as distance increases the quality will decrease. A lot of factors can determine the maximum cable length, but for low resolutions (up to 800x600) you can reach 100 feet and beyond without too much trouble. For mid-range resolutions of 1280x1024/1024x768 you can typically reach somewhere between 50 to 100 feet.
Attenuation in state-of-the-art fibers has declined steadily since then, reaching 0.5 dB/km in 1976 and 0.2 dB/km in 1979. This last figure can be put into perspective by pointing out that for a fiber 10km long with an attenuation of 0.2 dB/km, about 63% of the light reaches the far end of the fiber.