My vision loss was said to be psychological because no physiological basis could be found. But the reason for the lack of physiological basis was inadequate diagnostic tools. Specifically, the doctor only could perform full-field electroretinography (ERG), which is unable to detect focal vision loss. Focal ERG, done years later, showed clear physiological basis, namely, greatly reduced photoreceptor responses in small regions of the central field. This, with no photoreceptor degeneration, is characteristic of occult macular dystrophy. Genetic testing confirmed that I have this condition. I likely inherited it from my mother, who had identical symptoms and wa also told it was psychological. Same with my brother. All three of us are now legally blind. My brother was from childhood, but my mother and I had 20/20 vision until late 20s. It sounds to me like maybe as many as half of people dismissed as faking it or being delusional had real visual deficits. I feel sad for those who, unlike me, may not have had the family support and knowledge of biology to be confident that the vision loss was not "just psychological". For conditions other than OMD, google "blindsight".