Seeing double

In a revelation that may seem more at home in a poetry collection than in a scientific journal, researchers have discovered that only identical twins see the same stars.

A study by Anglia Ruskin University researchers examined the vision of 69 sets of twins, including 36 sets of identical twins. 

They focussed on the optical defects which are found in every eye and slightly alter the way someone perceives the world. 

The research found that identical twins share identical optical abberations, even in the over 50s. Non-identical twins have different abberations. 

Study author, Dr Juan Tabernero, told OT that the results highlighted the strong genetic component influencing optical defects. 

“Our results were particularly striking if we take into account that our twins were mostly in their 50s and had been using their eyes independently from each sibling for a long time,” he elaborated. 

Larger optical defects like myopia or astigmatism were already known to have a strong genetic component, but little was understood about the genetics of small aberrations and optical defects that everyone has, Dr Tabernero explained. 

For example, he highlighted that aberrations were responsible for why people saw different stars when looking up at the night sky. 

“Now, we can say that only identical twins see identical stars,” Dr Tabernero concluded.