Swanandi Gawde, B.Optom, PGDOVS, ADCR, (M.Optom)

Optometry Faculty, ITM Institute, Navi Mumbai, India


Change Blindness is the phenomenon of failure to detect the change from the visual system. (1) Change blindness is a real-world as well as on-screen phenomenon, it occurs due to replacing people and different objects from the environment and changing characters from the display screen. Visual attention plays a major role in detecting the change from the real-world environment and on-screen display. In other words, it is how you are attentive while visualising the real world and on-screen things. (2)

Change blindness occurs when the local visual transient produced by a change is obscured by a larger visual transient, such as an eye blink (3), saccadic eye movement (4), screen flicker, or a cut or pan in a motion picture (5). A good example of visual attention is when you are watching a movie in which an actor is sitting in a cafeteria with a jacket slung over his shoulder. The camera then cuts to a close-up and his jacket is now over the back of his chair. But very few people are surprisingly poor at noticing these large changes to objects, photographs, and motion pictures from one instance to the next. (1)

Visual memory plays an important role in this scenario. The images are perceived at the level of the visual cortex, and they are stored in the form of visual memory. Very few of us could be able to recollect the memory in a fraction of a millisecond and find the exact change from a motion picture.

Visual attention is closely linked with detecting and identifying changes in the visual scene. (6) The presence of consciousness during change blindness helps individuals to locate the change in visual scenarios. Visual attention and consciousness are the psychology and neuropsychology of vision. When an observer pays attention to an object, they become conscious of its various attributes, and when attention shifts away from the first object the previous object seems to fade from consciousness. (7)

In visual attention, the observer sends their attention around the scene, on an item-by-item basis, until it reaches the item and changes the characteristics of the item. During this process, the individual is unable to see the change. In addition, there is a tight link between visual attention and consciousness. When a very silent object is presented for a few seconds, it sometimes goes unnoticed if visual attention is absent. The change has been unattended to the observer due to a lack of attention.

Moreover, in other words, paying visual attention usually improves the processing speed, lowers the detection threshold, or increases the response accuracy. Under certain conditions, the low special frequency stimuli can be better discriminated against without special attention. (8)

Visual Attention and Consciousness are both required more during the working memory, like detection and discrimination of unexpected and unfamiliar stimuli coming into the motion picture or ongoing scene. In some situations, you need attention but not consciousness, in cases of visual search, thought process, and already adapted things.

Consciousness must be needed to identify the change, where images pop out, iconic memory, animal, and gender detection, and partial reportability. The formation of After-images, Rapid vision, Accommodation Reflex, and Pupillary Reflex for all this attention and consciousness are not required.

Attention and consciousness are two closely related psychological concepts that are often conflated. Visual Attention and consciousness both works simultaneously while detecting the change from the field.

Attention deficit disorder is one of the most commonly diagnosed behavioural disorders in children, a label now given to 8.7% of children between the ages of eight and fifteen. Thus, Optometrists examining children with vision-based learning problems should keep in mind about the role of visual attention and consciousness in change blindness. (9)



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  2. Attwood, J. E., Kennard, C., Harris, J., Humphreys, G., & Antoniades, C. A. (2018). A comparison of change blindness in real-world and on-screen viewing of museum artefacts. Frontiers in Psychology9, 151.
  3. O’Regan, J. K., Deubel, H., Clark, J. J., and Rensink, R. A. (2000). Picture changes during blinks: looking without seeing and seeing without looking. Vis. Cogn. 7, 191–211. doi: 10.1080/135062800394766
  4. Grimes, J. (1996). “On the failure to detect changes in scenes across saccades,” in Perception: Vancouver Studies in Cognitive Science, ed. K. Akins (Oxford: Oxford University Press), 89–110.
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  6. Busch, N. A., Fründ, I., & Herrmann, C. S. (2010). Electrophysiological evidence for different types of change detection and change blindness. Journal of Cognitive Neuroscience22(8), 1852-1869.
  7. Van Boxtel, J. J., Tsuchiya, N., & Koch, C. (2010). Consciousness and attention: on sufficiency and necessity. Frontiers in Psychology1, 217.
  8. De Brigard, F., & Prinz, J. (2010). Attention and consciousness. Wiley interdisciplinary reviews: Cognitive science1(1), 51-59.
  9. Rensink, R. A. (2007). The Modeling and Control of Visual Perception. Integrated models of cognitive systems, 132-150.