What is tunnel vision?

Loss of peripheral: In tunnel vision, the peripheral portions of the retina lose their sensitivity and only the central portion remains (a tunnel straight ahead). Most often found in inherited degenerations like retinitis pigmentosa, some drugs can do this as well as rare retiinal infections. Advanced tunnel vision is very handicapping as victims cannot see their feet, or objects in view.

Keyhole view: Constriction of the peripheral visual field is often due to end-stage glaucoma, hereditary rp, and viral infections of the outer retina. Field expansion with a fish-eye lens or reverse telescope are possible, but at the cost of reduced acuity. Orientation and mobility training is recommended, even if the central vision is serviceable. See a vision rehabilitation specialist.