The conversation around sunscreen has evolved significantly, from being a “beach essential” to an everyday skincare staple. The application of sunscreen at home has always been a disputable issue, and
it is always preferable to be able to understand how the light exposure really works in our everyday environment.
Explaining how sunlight works, Dr Kashish Kalra, founder of Dr Kalra Skin Clinic, shares:
Sunlight consists of three types of ultraviolet (UV) rays:
• UVC rays: These are the most harmful, but fortunately, they do not penetrate the Earth’s atmosphere.
• UVB rays: These are responsible for sunburns and play a major role in skin cancer. However, they cannot penetrate glass windows.
• UVA rays: These are the real culprits behind pigmentation, melasma, premature aging, and fine lines—and importantly, they can pass through glass.
This distinction is crucial when discussing indoor sunscreen use.
Though it may sound far-fetched at first, wearing sunscreen indoors is not entirely exaggerated, especially in certain instances. Dr Nirupama Parwanda, Dermatologist & Founder of Zolie Skin, says “Glass windows allow ultraviolet (UV) radiation to penetrate, and affect the skin and cause premature ageing, pigmentation and long-term skin damage. It can even affect you when you have been spending much time next to the window, in a well-lit room or even in a place filled with natural sunlight, your skin is getting exposed.”
The issue of blue light exposure has been brought up due to increased screen time for many people. Blue light (400–700 nm) is known to cause pigmentation, especially in darker skin, through oxidative stress, but the impact from everyday screen exposure is minimal and still debated. This is a reason to switch to a broad-spectrum sunscreen protecting against UVA and visible light in cases when a person is likely to be hyperpigmented.
Lifestyle Matters More Than Location
Dr Kashish Kalra explains that your need to wear sunscreen indoor is less about being “indoors” and more about your daily routine and environment.
• Professionals like lawyers, architects, or those constantly commuting are exposed to intermittent sunlight throughout the day and should be more diligent with reapplication.
• On the other hand, someone working in a closed office setup with negligible sunlight exposure may not need to be as strict.
