Many people diligently apply sunscreen before heading outside but might wonder if the same protection is necessary when staying indoors. 

With growing awareness about skin health and UV radiation, this question has garnered significant attention. The truth is, wearing sunscreen indoors can be beneficial, especially when considering modern living conditions.

Why wear sunscreen indoors?

1. Understanding UV radiation

UV radiation consists of UVA and UVB rays. While UVB rays are primarily responsible for sunburn and are mostly blocked by windows, UVA rays can penetrate glass, according to Skin Cancer Foundation. These rays, which were once thought to be safe, can in fact contribute to premature aging, skin cancer development, and skin damage. If your home or office has a lot of natural light, you are likely exposed to UVA rays.

Early sunscreens only protected against UVB rays, but with the understanding of UVA's dangers, sunscreens now offer broad-spectrum protection. Make sure to opt for a broad-spectrum sunscreen if you're planning to wear it indoors. 

2. Blue light from screens

With increased screen time due to remote work and digital entertainment, exposure to blue light from computers, tablets, and phones is a concern. As per WebMD, studies have found that blue light from electronic devices can alter skin cells, leading to cell shrinkage and death, thereby accelerating the aging process.

Traditional chemical sunscreens usually don't protect against blue light. However, physical sunscreens with zinc oxide offer blue light protection and better UVA and UVB defense compared to chemical sunscreens, as noted by board-certified dermatologist Thomas Griffin Jr. in an interview with VeryWell Health.

3. Accumulative damage

Skin damage accumulates over time. Even small amounts of daily UVA and blue light exposure can add up, contributing to long-term skin issues. Consistent use of sunscreen indoors helps mitigate this cumulative damage.

Step-by-step guide to choosing and applying sunscreen indoors

1. Choose the right sunscreen

Select a broad-spectrum sunscreen that protects against both UVA and UVB rays. Look for one with an SPF of at least 30. 

If concerned about blue light, opt for a physical sunscreen that contains zinc oxide or antioxidants.

2. Cleanse your face

Start with a clean slate. Use a gentle cleanser to remove any dirt, oil, or makeup from your skin. This helps ensure that the sunscreen can adhere properly and provide effective protection.

3. Apply moisturizer

If your skin tends to be dry, apply a moisturizer suitable for your skin type. This step is particularly important if you're using a sunscreen with a matte finish, which can be drying.

4. Apply sunscreen generously

Squeeze out a nickel-sized amount of sunscreen for your face and neck. Ensure you cover all exposed areas, including your ears, the back of your neck, and any other parts that may receive light exposure.

5. Reapply as needed

If you're sitting near a window or exposed to significant UV rays even indoors, reapply sunscreen every two hours. Set a reminder on your phone to help remember.

6. Complement with other protective measures

Consider using window films that block UVA rays or wearing protective clothing. Close curtains or blinds during peak sunlight hours to minimize direct exposure.