New evidence has revealed that love may in fact be blind.
According to researchers at Florida State University in Tallahassee, US, people who are in love pay less visual attention to attractive people of the opposite sex.
In the study, the scientists asked 57 students in heterosexual relationships to write about occasions they felt extreme love towards their partner. Another 56 students wrote about feeling extreme happiness.
The students then viewed 500 microsecond flashes of 60 photos, comprising equal numbers of highly attractive men, highly attractive women, average-looking men, and average-looking women.
As the faces disappeared, a square or a circle appeared elsewhere on the screen.
The students were asked to identify the object as quickly as possible - a measure of a person's visual attention at a subconscious level.
Students primed with thoughts of love took significantly less time to identify shapes after viewing an attractive face of the opposite sex, compared with those who had written essays on happiness.
"We found that when people just thought about being in love with their current partner, their visual attention got repelled, rather than grabbed, by an attractive member of the opposite sex," New Scientist quoted Maner, as saying.
The finding may help explain why those in love do not seek out other, perhaps better, mates.
"[The repulsion] happens at the very initial stages of visual processing, at the very first moment they are aware of the photo," Maner said.
In the study, the repulsive affect was found to be so rapid, that the students would not have been able to exert conscious control over it.
Only attractive potential partners appear to have the repelling affect, as the two groups of students took the same time to identify the shapes when viewing average-looking faces, or faces of the same sex, the researchers said
The study is published in the journal Evolution and Human Behaviour.