Question
What’s the situation when a child occasionally has double eyelids?
Answer
Occasionally having double eyelids in children may be due to genetic factors. The gene that controls double eyelids is a dominant gene, usually represented by A, while the gene controlling recessive traits is a. Since children inherit one gene from each parent, there are three possibilities: AA, Aa, and aa. When dominant genes meet recessive genes, they manifest as dominant traits, which is the double eyelid. However, due to the involvement of recessive genes, the double eyelid may not be complete, resulting in occasional instances where a single eyelid becomes double. Eye shape is hereditary, with large eyes having a more dominant genetic trait than small eyes. For those with small eyes, this is undoubtedly a pleasant surprise because even if they have small eyes themselves, the possibility of their child having large eyes increases if their partner has large eyes.