So now we have an internet sensation: Heidi the resident "cross-eyed" opossum at Leipzig Zoo, complete with her own Facebook and YouTube appearances.
A spokeswoman at the Zoo has put forth the theory that Heidi's esotropia "could have come from a poor diet when she was young, causing large fat deposits to form behind her eyes". The white-haired marsupial has since been put on a diet and lost 400g of body weight.
Question: Are we witnessing a new type of strabismus?
Answer: Hardly. The photo above actually shows (1) corneal reflections are in the same 1 o'clock position, i.e., this is a case of pseudo-esotropia, commonly seen in babies in Asia; and (2) swollen conjunctiva in both eyes suggesting accumulation of fluids, or chemosis, which has further enhanced the esotropia illusion. Neither has anything to do with too much fat in the orbit. No crossed eyes here; instead, Heidi is probably suffering from some sort of allergies.