People with blue eyes might have a slight advantage in low light conditions.
- In the study, blue-eyed participants had a better ability to see numbers and letters in dimmer lighting after being plunged into darkness.
- This adaptive advantage would be linked to an increase in stray light in depigmented irises.
- Further research needs to be conducted to determine the association between melanin content and low-light visual acuity.
We see more or less well in the dark depending on the color of our eyes. This is the conclusion of a recent study published on the site BioRxiv. As part of this work, researchers from Liverpool John Moores University (England) wanted to determine the effect of iris pigmentation in people with blue eyes and brown eyes on the ability to see in low light conditions. after a period of short-term dark adaptation.
Better night vision due to increased stray light in depigmented irises
For this, the team recruited 40 adults. Their eye color was self-reported and then verified using a recently developed classification guide. Next, participants performed a 30-second eye test under decreasing light intensities. After being in darkness, the lighting was increased until the volunteers could see a sequence of numbers and letters on a wall three meters away.
According to the results, adults with blue eyes had a better ability to see numbers and letters in dimmer lighting after being plunged into darkness than people with brown eyes, “meaning that depigmented irises likely provide an adaptive advantage.” According to the scientists, this advantage could be the result of increased stray light in depigmented irises, “which, in terms of luminance, is disadvantageous, but can be an advantage in low light conditions.”
Determining the precise relationship between melanin content and low-light visual acuity
Despite these data, the team believes that additional research is needed to determine the specific association between melanin content and low-light visual acuity. Additionally, further work needs to be done to establish that the improved ability of blue-eyed adults to see in low-light environments observed in this study is truly attributable to iris pigmentation.
