The projector is imaged by projecting a beam of light to a white wall or curtain and then diffusely reflected, which will cause less damage to the eye than the form in which the TV light shines directly on the eye.
But be aware that it is relative, not absolute. This also shows that using a projector to watch movies for a long time will cause some damage to the eyes, whether it is turning on the light or turning off the light to watch, but the damage is smaller than that of the TV.
In general, low brightness projectors, will be more susceptible to the influence of ambient light, resulting in dark screen, affecting the viewing experience, which makes many consumers will choose to turn off the lights to watch, in order to pursue a better viewing experience, but this burden on the eyes is greater, to know that in the ambient light is too dark to see things, it is definitely hurtful.
Therefore, it is still recommended that you try to choose a projector with sufficient brightness to resist ambient light, and you can also add an anti-light curtain if you have the conditions, so that you can not only turn on the lights to see, even if it is enough to watch movies during the day. In the case of sufficient brightness, choose a high resolution, so that the projected picture will be clearer and friendlier to the eyes.
At this point, it should be possible to conclude that watching the projector in a dark environment will bring a more immersive viewing experience, but it is not recommended to keep watching for a long time.
In the final analysis, the point where the display device hurts the eye lies in the eye distance, duration and posture. However, due to the principle of diffuse reflection, the projector has greater benefits compared to other display devices after solving the ambient light problem.