A Causasian man showed a rare case of regaining functional vision. This man had blood in its anterior chamber of the eye (a condition known as hyphema) and due to this blood he had abnormally high blood pressure in the eyeball. Moreover, the light sensitive back of the eyeball was detached and there was no light perception vision. He was also the patient of diabetes mellitus.
This Caucasian patient was taken to New York Eye and Ear Infirmary and following surgery his vision improved to counting fingers vision in the right eye at five metres.
Researchers have concluded that functional vision can be regained despite long-standing retinal detachment.
Reference and further reading:
Olawoye, O. et al. (2011). Visual recovery in a patient with total hyphema, neovascular glaucoma, long-standing retinal detachment and no light perception vision: a case report. Journal of Medical Case Reports, 5:221.