One of these eyes is not like the other. There have been alert viewers on Facebook who have noted abnormal family photos, who have alerted the parents to seek medical treatment. The diagnosis was retinoblastoma. Photo is from American Academy of Ophthalmology website and is available for viewing on their website. In this photo, the eye should be red, hence we use “red eye reduction” to touch up photos. When only one eye has it, there could be a medical problem.
We call this the kindergarten sign, i.e. where one of the sides is not like the other. You don’t have to be a doctor to help save a life.