The researchers detected prions in the eyes of all 11 patients. What’s more, they found prions in all eight regions of the eye that were tested, including the eye’s cornea, lens, ocular fluid, retina, choroid (a part of the eye that contains blood vessels and connective tissue), sclera (the white of the eye), optic nerve (which connects the back of the eye to the brain) and extraocular muscle (which controls eye movement.) The highest levels were found in the retina, the area of light-sensitive cells located at the back of the eye. In some cases, levels of prions in the retina were close to those seen in the brain, the researchers said.

Infectious ‘Prions’ Found in the Eyes of Patients with Fatal Brain Disease | Live Science