Effects and Challenges of Operational Lighting Illuminance in Spacecraft on Human Visual Acuity

For large-scale manned spacecraft bound for the Moon and Mars, lighting should be explored that can reduce safety risks while increasing visual capability. The use of appropriate lighting in large-scale manned spacecraft can provide astronauts with a comfortable and safe living and working environment while reducing the energy consumption of the lighting equipment. Visual acuity is an important aspect of the quality of the light environment. It directly determines the human eye’s ability to discern details and has an important impact on visual ergonomics and the efficiency of receiving visual in-formation. In this study, we investigated changes in the human eye’s visual acuity in a simulated spacecraft environment under three illuminances. 18 healthy persons participated in the study and tested binocular vision under three illuminance light environments. The results show that the amount of change in visual acuity decreased as the illuminance value increased, the rate of decrease gradually slowed down and eventually tended to be flat. We found that with 200 lx as the dividing line, increasing the illuminance value at low illuminance can significantly improve visual acuity.