Final answer:
Blue light exposure on facial skin should be used cautiously and for limited duration to avoid disruptions to the body's natural sleep-wake cycle.
Step-by-step explanation:
When using blue light on the facial skin, it is important to consider the duration to avoid potential negative effects. Recent studies have found that blue light exposure can disrupt the function of the adrenal glands and impact human circadian rhythms.
Therefore, it is recommended to limit the use of blue light on the facial skin to avoid potential disruptions to the body's natural sleep-wake cycle. It is best to consult with a dermatologist or healthcare professional for specific guidance on the duration and usage of blue light for skincare purposes.