Health impacts of daylight saving time

Initial research highlighted a range of adverse health outcomes linked to the bi‑annual clock change, noting spikes in heart attacks, motor‑vehicle fatalities and workplace errors in the week after the spring shift, as well as increased anxiety and mood disturbances. A separate analysis of over 12.6 million health records found that retinal vascular diseases, including proliferative diabetic retinopathy and neovascular age‑related macular degeneration, rose by roughly 30 % in the weeks following the spring transition, while the autumn shift was associated with a 20 % drop in retinal vein occlusion cases.

A later study focusing on U.S. adults reinforced the retinal findings. Using insurance‑claim data for more than 18 million people, researchers observed a 20‑30 % rise in the same retinal‑vascular conditions after the spring shift and a 20‑40 % reduction after the fall shift. The authors suggested that gaining an hour of sleep may protect against these diseases and called for closer clinical evaluation of patients presenting symptoms after the spring change.