Interesting. I wonder if it has something to do with eye muscles relaxing more in low light environments causing a long term change in the shape of the eye. Kind of like the correlation between prescription strength and how long people have been wearing glasses for. Then again it would be hard to differentiate between the natural changes due to muscular entropy. I suppose there could be a long term study involving light therapy or something. https://www.sciencedaily.com/releases/2020/06/200629120241.htm