Six year olds with a squint may not be so welcome at birthday parties in comparison with peers who have normally aligned eyes, according to recent research.
The findings prompt the authors to suggest that corrective surgery should be performed not later than the age of 6, which is when the discrimination seems to emerge.
The Swiss researchers digitally altered photographs of six children from six identical twin pairs to create inward and outward types of visible squint (strabismus) to compare against normally aligned eyes.
One hundred and eighteen children between the ages of 3 and 12, who were either patients at an eye clinic or the siblings of patients, but with normally aligned eyes, were then asked to select which of the identical twins they would be prepared to invite to their birthday party.
They were asked to make a choice four times, giving them the chance to select the faces of up to four children with a squint. If squints were to make no difference to selection, an average selection of two children with a squint would be expected, say the authors.
Factors, such as the colour of the top the child was wearing, gender, or the type of squint s/he had made no difference to the likelihood of selection.
And children under 6 didn't make any distinction between the twins with a squint or normally aligned eyes.