It is normal to have vision loss in the periphery

“Patients with degenerative retinoschisis need to know that they may have areas
of peripheral visual loss, corresponding to the area of the retina where splitting has
occurred, but these areas of visual loss are almost always stable.”

If you have Denegerative retinoshisis don’t be convinced that you have a retinal detachment just because you did not pass the test of counting fingers over your head. It’s normal to have vision loss in the peripheral.

Source: Wikipedia

Browning ,David J. MD,Phd What you should know abou Degenerative Retinoschisis. Retrieved from pdf file: