Prevalence and Risk Factors

What is Nonorganic Vision Loss?

Nonorganic vision loss (NVL)—previously known as functional or hysterical vision loss—is subjective vision loss that does not comport with a recognized pathologic process.

Prevalence

Some reports suggest that approximately 10% of neuroophthalmic patients may have NVL, although half of that population is often accounted for by patients with organic pathology and functional overlay.

Risk Factors

It is difficult to clearly define risk factors for NVL. Disability claims are a poor predictor, with widely variable rates of claims by patients with NVL being reported (14% to 86%). Somewhat counterintuitively, a history of prior psychogenic illness should not influence suspicion for NVL. Vision complaints in patients with prior nonorganic illness are sometimes assumed to be
nonorganic by default, leading to diagnostic error and missed organic pathology.