What is the lux level limit which is bearable by unaded eye?
i’ll not be using numerical data to answer your question, because damaging of the tissues of our eyes can be done by exposure to lower intensity light also, for a longer period of time. Basically, the more concentrated the light is, the more damage it can do. Tissue damage is attributed to a number of factors. Lazer beams can cause loss of vision, when incident upon the eyes. Analyzing the light spectrum, we can conclude that concentrated red beams have higher wavelength and lower energy, whereas concentrated blue beams have lower wavelength and higher energy! So, the ordinary red lazer beam of considerable intensity may not cause any tissue damage when incident for a short period, but a blue lazer may cause permanent eye-tissue damage! you should understand the meaning of intensity first. Its basically the energy transferred by a source per unit area. Since red light has lower energy, damage is not inevitable, i.e not certain. But, blue light, having high energy can cause significant damage!
400 to 500 lux is suitable for room.