Exposure to bright light can indeed affect night vision, but the extent to which red light impacts it can be different. Human eyes adapt to low light through a process called dark adaptation, which involves both the pupils dilating and the photoreceptor cells in the retina adjusting. This process can take around 20 to 30 minutes to reach optimal sensitivity.
Red light is often used in environments where preserving night vision is important, such as in astronomy or during nighttime operations, because our eyes are less sensitive to longer wavelengths of light. This means red light has a lower impact on the rod cells in the retina, which are responsible for night vision. However, if the red light is too bright or the exposure is prolonged, it can still affect your night vision by causing the pupils to contract and slowing down the adaptation process.
It’s important to use a dim red light, as this minimizes the reduction in dark adaptation. In contrast, exposure to white or blue light significantly decreases night vision because these shorter wavelengths are more efficiently detected by the cone cells, which respond primarily to daylight. Therefore, opting for a low-intensity red light source is generally considered best practices for maintaining night vision.