HELP !!! i want to buy grey contact lenses but they eye measure stuff ?

OK READ - so i hate my eye color there dark brown there from my mum's eyes i want the same eye color as my dad a bluish greyish eye color contact lenses but anyway it says when i buy them like it says on the order thing left eye and right eye and then theres heaps of all these numbers for the eye measurments and stuff i think ok then well anyway i don't know how to measure them and i don't want to go to the opertometrists like what if i say to them i want to measure my eye for contact lens and then they might say what is she talking about then they'll think i'm crazy !!! then i'lll be embarrased so any other way to do it and iif i do get to do it at the opertomitrists will it hurt but anyway becuase i'm too scared too ask them too ? pls get help for me pls ! thx :)