What does it mean that I have 'recessed orbits'?

Corneal topographers require the patient's eye to be very close to the machines to acquire data. In some cases, a patient is not able to be positioned correctly in the chair, because of a wheelchair or body habitus for example, to allow the machine to get an accurate reading.

If a patient has "recessed orbits," that implies that although the patient is able to position himself correctly, the anatomy of the orbit puts the location of the eyeball slightly too far back in the skull for the machine to acquire the data. Thus, an accurate corneal topography would not be able to be performed.