The distance at which stars are visible to the naked eye depends on various factors, including the brightness of the star, atmospheric conditions, and light pollution. In optimal conditions, away from light pollution and with clear skies, the human eye can see stars that are several thousand light-years away.
Light pollution caused by artificial sources, such as streetlights, buildings, and other human-made sources of light, can significantly impact our ability to see stars. It creates a veil of artificial brightness in the night sky, which reduces contrast and makes fainter stars less visible.
In heavily light-polluted areas, such as urban centers or areas near cities, the visibility of stars can be severely limited. The bright artificial lights overpower the faint light emitted by distant stars, making it challenging to see all but the brightest stars and a handful of the most prominent constellations.
However, in areas with low light pollution, such as remote rural locations, deserts, or open ocean, the visibility of stars can be significantly improved. Away from the glare of artificial lights, the night sky becomes darker, allowing for a clearer view of stars and celestial objects. In such areas, it is possible to see a multitude of stars, including dimmer ones that are not visible in light-polluted regions.
To mitigate the effects of light pollution and enhance stargazing opportunities, some regions designate dark sky parks or reserves, which implement lighting regulations to reduce light pollution and preserve the quality of the night sky.
It's worth noting that telescopes, binoculars, or other astronomical instruments can help magnify the light from distant stars and reveal even more celestial objects, enabling observations of stars that may be too faint to see with the naked eye, regardless of light pollution.