Why do transition lenses go dark in sunlight when you’re outside but not when you’re in a brightly lit room?

Question

Why do transition lenses go dark in sunlight when you’re outside but not when you’re in a brightly lit room?

In: 12

Answer 1

The brightness of an indoor room is minuscule compared to direct sunlight.

* 32,000–100,000 Lux Direct sunlight
* 1,000 lux overcast day, TV studio (bright lit)
* 300-500 lux office
* 100 – 150 lux typical living room

Your vision system is adaptive so you do not notice the huge difference in illumination indoors compared to outdoors.