Regarding the stars in the sky at night, I have read a lot of times about the "false" image we get from it. Mainly due to gravitational lensing and stars that no longer exists altough their light is still there. But, how is it possible then that, as I far as I know, the constellations are shown in their actual shape from the earth? Are they free from the effects formerly mentioned?? Probably the question sounds naive, but I was not able to sort it out through Google.