Glass, Sunlight & Human Health

In the first episode of Series 2, we’re joined by daylighting expert and chemical engineer Joe Menchefski to explore a critical but often overlooked topic in modern building design: glass.

While low-E glass and LED lighting have dramatically improved energy efficiency, emerging research suggests they may also filter out parts of the light spectrum essential for human health.

Are our buildings optimized for energy — but not for biology?

🌞 What We Cover

• Why humans now spend 90–95% of their time indoors
• How low-E glass works — and what it blocks
• The possible link between filtered light and rising childhood myopia
• Why full-spectrum sunlight matters for eye development
• The impact of LED lighting on circadian rhythms
• Blue light, red light, and mitochondrial health
• The balance between energy efficiency and human wellbeing
• Vacuum-insulated glass (VIG) as a potential breakthrough
• Passive design, orientation, and smarter daylight strategies
• Why architects are beginning to rethink glass design

🔬 Key Themes

• Full-spectrum natural light is not just visual — it’s biological
• Buildings without proper daylight may impact sleep, metabolism, and productivity
• Energy efficiency alone is not a complete design strategy
• Health-optimized building design is an emerging frontier

🏗 Why It Matters

From rising myopia rates in children to circadian disruption in adults, the way we design windows, façades, and lighting systems may be shaping long-term public health outcomes.

This episode kicks off Series 2 by asking an essential question:

Are we designing buildings for performance metrics — or for people?

Read the accompanying blog here: https://shadowmap.org/learn/are-our-windows-making-us-sick

Sunlight Matters is a podcast exploring the role of the Sun in human health, architecture, cities, and everyday life.

Through conversations with scientists, architects, and technologists, the series examines how natural light shapes our bodies, our buildings, and the way we live indoors.

Hosted by Dave Wallace, Sunlight Matters asks a simple but overlooked question: what happens when we disconnect from the Sun?

Because sunlight isn’t optional. It matters.

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