On my podcast, Fifty Words for Snow, my co-host Emily John Garcés and I usually explore words from other languages that have no direct English equivalent. Words that open windows into other ways of perceiving the world. But in one recent episode, we tried something different. We borrowed words from the field of vision.
The word we focused on was scotoma, a term from ophthalmology that means a patch of blindness in the field of sight. Every human eye has one. It is the point where the optic nerve exits the retina and no image can form. We do not see the hole because the brain fills it in. Ralph Levinson, a retired ophthalmologist and our guest that week, called this “a profound statement …
On my podcast, Fifty Words for Snow, my co-host Emily John Garcés and I usually explore words from other languages that have no direct English equivalent. Words that open windows into other ways of perceiving the world. But in one recent episode, we tried something different. We borrowed words from the field of vision.
The word we focused on was scotoma, a term from ophthalmology that means a patch of blindness in the field of sight. Every human eye has one. It is the point where the optic nerve exits the retina and no image can form. We do not see the hole because the brain fills it in. Ralph Levinson, a retired ophthalmologist and our guest that week, called this “a profound statement on life and cognition.”
Our eyes edit reality. What we believe we see is not simply received but imagined. The mind is painting over the gaps, projecting continuity where there is none.
The Blind Spot Beyond the Eye
Ralph told us that scotoma has a second, figurative meaning in psychiatry. It refers to a blind spot in awareness, a part of the psyche that cannot perceive its own omission. We all carry these unseen pockets of unknowing. They might appear as habits, prejudices, or assumptions we do not think to question.
He mentioned a book called The Blind Spot: Why Science Can’t Ignore Human Experience, which argues that even science, for all its precision, has its own blind spots. Instruments can measure neural activity, but not the private experience of pain. We can record a brain’s reaction to chocolate, but not the flavor as it melts on the tongue. The measurable and the meaningful do not always align.
The book makes a point that resonated with me. No matter how advanced our tools, our perception of the world is always shaped by the instrument doing the perceiving, which in our case is the human body and mind.
Enter the Umwelt
The German word umwelt describes this perfectly. It means the sensory world unique to a given creature. A bat experiences the world through echolocation. A dog’s world is built from scent. Humans navigate primarily through sight. Each species lives in its own perceptual bubble, unaware of what lies outside.
Once you recognize this, humility follows. You stop assuming that everyone sees the same world you do. Even within the human family, each of us has a different sensory and emotional aperture, a slightly different angle on reality. My dog and I can occupy the same room and have entirely different experiences of it. So can two people in a marriage, a friendship, or a conversation.
Living With Our Missing Pieces
After we finished recording, Emily and I kept talking about how our minds fill in what is absent, not just visually but emotionally. We invent stories to make sense of gaps. We assume motives, imagine explanations, and smooth over uncertainty. It is a kind of psychic patchwork that helps us move through the day.
Recognizing this does not make the blind spot disappear, but it softens our certainty. As Ralph said, if you know you have a blind spot, you still have it, but you also have awareness. You become curious again.
Our inner and outer worlds are stitched together from what we can perceive and what we cannot. The mystery in that is not a flaw but a feature of being alive. Awareness does not mean seeing everything. It means remembering that there is always more to see.