If both parents have double eyelids, the chances of having a child with double eyelids are high, but there are also chances of having single eyelids. This is because single and double eyelids are influenced by genes. The double eyelid gene is dominant, and parents with single or double eyelids have a dominant gene, or they can carry a recessive gene, which is the single eyelid gene. For example, if the father’s eyelid gene is AA and the mother’s is also AA, the child born from the combination of the two must also have an eyelid gene of AA, which means double eyelids. If the father is not double eyelid, but single eyelid gene carrier is Aa, (where a means single eyelid gene) the mother also carries the gene Aa, then the combination of the two children, may be double eyelid gene AA, may be single eyelid gene carrier Aa, may be single eyelid gene aa. If the gene for double eyelids and the gene for carrying single eyelids are both present, the child will have double eyelids, but if the child’s gene is the gene for single eyelids, aa, the child will have single eyelids. So if both parents have double eyelids, the child may not always have double eyelids, and there is a small chance that the child will have single eyelids.