Should I wear sunscreen indoors?

UVB — the burning wavelength — is largely blocked by window glass. UVA — the wavelength that drives pigmentation and photoaging — passes through most glass and reaches skin in meaningful doses during long stretches near windows. Home offices with direct window light are the most common exposure context people underestimate.

Interior-room exposure (away from windows) is low enough that daily SPF is less critical. For most office-in-the-window Australians, however, the daily-SPF habit is worth keeping.

What to watch

• Where your desk sits relative to a window
• Whether your pigmentation scores trend in the same direction on work-from-home days as on office days
• Whether one side of your face shows more pigmentation than the other (window-side exposure is often the cause)

The Stella take

SPF indoors isn't universally required, but "I never go outside" isn't a reliable reason to skip it. Test your actual exposure by checking whether one side of your face pigments more than the other over a season.

Appearance-level observations, not therapeutic advice. Not a medical device.