Cysts without lining of epithelium can be found outside the orbital tissues. Of these, perhaps the best known are hydatid cysts of the liver, blood cysts of the breast, subdural blood tumors of the cranial cavity and, within the eyeball, cysts of the retina and serous cysts of the iris. A few types of cyst without epithelial lining within the orbit and outside the globe have been studied, and several reports of such cysts have been published. Examples of these are serous or exudation cyst, parasitic cyst, congenital cyst of the orbit associated with microphthalmos or with coloboma, cyst in the sheath of the optic nerve1and blood cyst. A serous cyst of the orbit may have its origin in the bursa between the tendon of the superior oblique muscle and the trochlea or in the bursa between the levator muscle of the upper eyelid and the superior rectus