In the new study, published this week in the Journal of Opthalmology, researchers noted that night-vision disturbances of the 67 people they tested increased after drinking a "quality" wine, with effects similar to those caused by ageing.
Contrast sensitivity and the ability to discriminate details under low light conditions were found to be reduced.
The team lead by José Castro found that alcohol also caused actual physical changes in the eye.
Tears are shaped by a liquid film which was affected by the presence of alcohol (ethanol) in the tears after heavy drinking.
The scientists speculated that ethanol in the tear film makes it easier for water to evaporate, reducing the tear's volume, creating 'scattering' and optical aberrations such as haloes and starbursts around light sources such as car headlights and traffic signals.
They found optical aberrations occurred in subjects with breath alcohol above the Spanish legal limit of 0.25mg/l.
"These results could be taken into consideration in such fields as driving, where it is of vital importance to evaluate the visual abilities of the subject," the researchers said.
This is important "especially under night-time conditions, where physiological changes and visual alterations occur".
Don't miss stories about Spain, join us on Facebook and Twitter.