If the eyelash looks reasonably sharp then it's on the focusing screen, which is where most of this stuff gets anway. While it's irritating, it wont be affecting your shots. My preferred method of dealing with dust on the screen is to use a static brush such as the Arctic Butterfly. Blowers are OK but they do tend to just redistribute the dust.
It's possible ( but less likely) that the eyelash has somehow found it's way onto the other side of the focusing screen, inside the prism housing in which case the screen needs to come out to get at it.