Oliver Sacks' "The Mind's Eye": Blind Perception and Inner Vision

Overview: Perception and the Mind's Eye

Oliver Sacks observes that perception and visual sight are closely related, and if this is the case, then we all "see" in a certain way even if we do not literally see. Because perception and sight are linked, this explains how language can enable us to "see" and communicate with others even when we are not physically looking at the stimuli in question — we are mentally visualizing them with our mind's eye.

This also explains why blind people can frequently describe objects and phenomena with a more vivid and striking detail than sighted people can. They are not distracted by extraneous details. Rather, they absorb impressions in their mind's eye, deliberate on them, and deliver a final rendition. The result is a vivid and often intensely accurate representation of the original.

The fascinating conclusion of Sacks' essay is that so-called blind people may actually be more sightful than sighted individuals themselves. Blind people are often encouraged to transfer their abilities toward strengthening their other senses, and thus to "see" through those means. This may, however, be misleading. Blind people have often retained a great deal of their original sight and can still see in an internal way. This capacity continues to serve them and should likely be the talent that is most focused on.

Finally, each blind person — as does each individual in general life — sees in a different way. We are idiosyncratic and unique in our mental and physical visualization. Definitive conclusions can never be drawn, but the visually impaired are more visually enhanced than we typically assume. They may, in fact, be more visually enhanced than the sighted. They see in their mind's eye.

Vision as Perception: Sacks' Core Argument

A renowned neurologist, Sacks was perplexed to find that the experience of the visually impaired differed from what he had previously believed it to be. It is commonly thought that vision enables one to see and that once vision is lost, blind individuals are impaired for life — unless vision is restored by surgery — and must accept their condition by compensating through their remaining senses.

Sacks was, however, astonished to discover that not only did blind people repeatedly tell him that they were able to see, but their descriptions of their perceptions showed that they saw as clearly as before and sometimes more vividly and graphically than sighted people did.

One example Sacks provides is that of William H. Prescott's Conquest of Peru and Conquest of Mexico. Reading those works when young, Sacks felt that he himself had visited those lands, owing to the author's "intensely visual, almost hallucinogenic descriptions" (p. 239). Years later, he was astonished to discover that not only had Prescott never visited those lands, but that he had been virtually blind since the age of eighteen.

A clinical case of perception persisting after sight has been lost comes from a 1978 study of patients who could not see to their left side. As Sacks recounts:

"When they were asked to imagine themselves walking down a familiar street and describe what they saw, they mentioned only the shops on the right side of the street; but when they were then asked to imagine turning around and walking back, they described the shops they had not 'seen' before, the shops that were now on the right side." (p. 228)

Equally striking is a 1911 clinical case in which English neurologists Henry Head and Gordon Holmes found blind spots within patients' visual fields that corresponded exactly to blind spots "in exactly the same locations" (p. 229) in those patients' mental imagery as well.

On the basis of these and similar instances, Sacks concluded that seeing is inseparable from perception. The two are intimately connected. A blind person may have lost his vision, but his perception remains. And because the blind person ruminates repeatedly on his perceptions until he has internalized them in his mind's eye, he often holds a clearer picture of the target stimuli than a fully sighted person might. Paradoxically, therefore, blind people may be more sighted than sighted individuals.

Individual Differences in Blind Visual Experience

Sighted people import and translate stimuli according to their particular experiences, which gives each person a different context and causes each individual to interpret stimuli in their own way. People tend to think of a "blind" person as someone who has utterly lost the capacity for vision. The term has made its way into various idioms: we say that someone is "blind" to reality or "blindly" in love, meaning that the person's perception is so clouded in a particular respect that they simply cannot see what others see clearly.

Sacks shows that this characterization is inaccurate. Not only can blind people still see — and sometimes see better than sighted people — but they can also see in their own idiosyncratic way. Just as sight differs in its expression from one sighted person to the next, so too does internal vision differ among the blind.

Sacks reflects on four memoirs he had read, each strikingly different in its depiction of the visual experience of blind individuals:

"Hull with his acquiescent descent into 'deep blindness'; Torey with his 'compulsive visualization' and meticulous construction of an internal visual world; Tenberken with her impulsive, almost novelistic visual freedom… and Lusseyran, who identified himself as one of the 'visual blind'. Was there any such thing, I wondered, as a typical blind experience?" (p. 216)

The visual experience of the blind differs just as much as the visual experience of the sighted individual does. There is no singular blind experience, just as there is no singular sighted one.

Conclusion

The Mind's Eye is a fascinating treatise on how blind people are actually far more sightful than we take them to be. In fact, blind people may actually be more sightful than sighted individuals themselves. Blind people are often encouraged to transfer their abilities toward strengthening their other capacities, and thus to "see" through those alternative means. This may, however, be misleading. Blind people have often retained a great deal of their original sight and can still see in an internal way. This capacity continues to serve them and should likely be the talent most focused on.

Each blind person, as does each individual in general life, sees in a different way. We are idiosyncratic and unique in our mental and physical visualization. Definitive conclusions can never be drawn, but the visually impaired are more visually enhanced than we typically recognize. They may be more visually enhanced than the sighted. They see in their mind's eye.

Source: Sacks, O. (2010). The Mind's Eye. Knopf.