New Jersey Cosmetology and Hairstyling Practice Exam

Which type of light is most harmful to the skin?

1. Infrared light

2. Visible light

3. Ultraviolet (UV) light

4. X-ray light

The correct answer is: Ultraviolet (UV) light

Ultraviolet (UV) light is regarded as the most harmful type of light to the skin due to its ability to penetrate the skin and cause cellular damage. UV light is divided into two primary categories: UVA and UVB rays. UVA rays can lead to premature skin aging and contribute to the development of skin cancers, while UVB rays are primarily responsible for sunburn. Both types of UV radiation can damage the DNA in skin cells, which can lead to mutations and an increased risk of skin cancer over time. Unlike infrared light, which primarily generates heat and does not have the same level of damaging effects on skin cells, UV light specifically targets the skin's deeper layers. Visible light is less harmful compared to UV, as it does not have the same capability to cause chemical changes in skin cells. X-ray light, while harmful in other regards, typically penetrates deeper tissues and organs rather than directly causing skin damage in the way that UV light does. These aspects illustrate why ultraviolet light stands out as the most harmful to the skin among the various types of light.