Hillevi Hemphälä, a light researcher at Lund University, highlights the emerging concerns regarding the flickering of energy-efficient LED lights replacing traditional incandescent bulbs. She suggests that many of these LED fixtures emit harmful light variations that can potentially trigger the brain's pain centers, leading to negative health effects over time. Common symptoms reported include dizziness, headaches, and migraines, particularly associated with dimmable LED lights.

Hemphälä estimates that around half of all LED bulbs exhibit an invisible flicker, which she believes to be a significant public health issue, affecting, according to her research, as many as one-third of the population. Her personal experience reflects this concern; being sensitive to invisible flickering, she recently discovered that the new LED lighting in Stockholm's subway trains causes such flickering, compelling her to shield her eyes from the discomfort.

The implications of this research underscore a vital but often overlooked aspect of modern lighting technology and its effects on health, pushing for further inquiry into acceptable standards for LED lighting in public spaces like transportation. Hemphälä’s findings invite discussions on how we may need to reevaluate our shift toward energy-efficient lighting to consider the well-being of those who are adversely affected by such technological advancements.