Six-year-old children with strabismus are much less likely to be invited to birthday parties than children of the same age without strabismus, according to a study in the August 18 online edition of the British Journal of Ophthalmology.

The researchers digitally altered photographs of six children from six identical twin pairs to create the appearance of strabismus to compare against twins with normally aligned eyes. Then, the researchers asked 118 participants aged three to 12 to select which of the identical twins they would prefer to invite to their birthday parties. The participants were each instructed to make four selections.

At the end of the study, the researchers determined that participants under the age of six years did not have a statistically significant selection preference between twins with strabismus and those without. Of 31 participants aged four to six years, just one did not select a child with strabismus.

However, about one-third of participants aged six years or older (18 out of 48) selected children with normally aligned eyes over children with visual strabismus.

Furthermore, following selection, the researchers asked the participants whether they had noticed anything particular about the appearance of the twins. Just 19% of the four- to six-year-olds mentioned “eye alignment” compared to 48% of the six- to eight-year-olds.

The researchers concluded that children with strabismus are less likely to be accepted by their peers, and recommended that children with the condition undergo corrective surgery before the age of six to avoid potentially negative social implications.

Mojon-Azzi SM, Kunz A, Mojon DS. Strabismus and discrimination in children: are children with strabismus invited to fewer birthday parties? Br J Ophthalmol. 2010 Aug 18. [Epub ahead of print]