Stars that we can see with the naked eye are a few hundred to a few thousand light years away. That means that light from the most distant stars that we can see with the naked eye is only a few thousand years old, at most. However, stars live for millions or even billions of years, depending on their mass - with the smaller, less massive stars living the longest. Indeed, even the shortest-lived stars - giant stars several times more massive than the Sun - live at least for a few million years. Therefore, the chances that a star observed with the naked eye died since its light began its journey are very slim. For distant galaxies, which can be millions or billions of light years away, it is of course much more probable that some of the stars within that galaxy might have died by the time that their light reaches us.