Anuska Chakraborty, B.Optom (Pursuing)

Student, NSHM Knowledge Campus, Kolkata, India


“Hey! How was your day?” a person asks you. You trying so hard to remember, whether you know him or not? Has he any similarity with any of your colleagues or he just a stranger? Have you ever experienced such incidents? If yes, don’t worry! you are not alone! It can be present in one in every 33 people, congenitally.(1) This condition is known as Face Blindness or Prosopagnosia.

Prosopagnosia is a visual agnosia characterized by an inability to recognize previously known human faces and to learn new faces.(2) It can result from ischemic stroke, injury in the occipitotemporal part of brain or certain neurodegenerative diseases (e.g., Alzheimer’s disease, Parkinson’s disease). But in rare cases, Prosopagnosia is present at birth, even in the absence of brain damage. Congenital prosopagnosia can be caused by genetic mutations or deletions as it tends to run in families.(3)

Broadly Visual Agnosia can be classified into two types : Apperceptive & Associative agnosia.

Apperceive agnosia occurs when there is no perception, while associative agnosia occurs when there is perception but not recognition. For example, if you present multiple pictures of the same cat to a person with apperceptive agnosia, they would neither be able to identify,  nor they would recognise that it’s the same picture⁴. On the other hand, if you show the same set of pictures to someone with associative agnosia, they will recognise the similarity among the pictures present, however  they will not be able to identify the object in the picture as a cat.(4)

A person who has  apperceptive or associative prosopagnosia, basically faced such problems with human faces, which cannot be perceived or recognised. Apperceptive prosopagnosia is observed in patients with posterior cortical atrophy (PCA), pathologically considered as Alzheimer’s disease, and associative

prosopagnosia in frontotemporal lobar degeneration (FTLD).(5)

Let’s know about other types of Agnosia

There are other specific types of visual agnosia present where patients cannot perceive or recognise a certain type of objects.(4)

  • Akinetopsia: when a person can’t recognise a moving object; but can see the object
  • Alexia: people can’t read; but can see, write & spell the letters
  • Autopagnosia: a person can’t recognise their own body parts, most commonly finger agnosia is seen
  • Achromatopsia: when a person can’t identify different colours
  • Environmental agnosia: a person unable to recognise or describe a familiar location
  • Form agnosia: when a person can  see the parts but can’t recognise the whole object
  • Dorsal simultanagnosia: when a person can only see one object at a time; if he isn’t focusing on the object, he will then not  perceive it
  • Ventral simultanagnosia:  when a person can see multiple objects at a time, but can identify them individually only
  • Social-emotional agnosia: a person can’t recognise nonverbal cues, like body language

Overall agnosia is very rare, less than 1% of people have any type of agnosia. Visual agnosia is the commonest form of agnosia; however, the agnosia can also present as Auditory or Tactile or Olfactory or even Gustatory also.

Don’t worry it’s not just you

The condition might be congenital or could also be acquired in the later stages of life due to some injuries. Unfortunately, prosopagnosia is irreversible, but handling situations tactfully is the key to overcome this condition. According to the people who have been experiencing this condition, you just need to be an excellent observer. Paying attention to the voice note, hair & clothing style, and specific body language or you can also ask your close ones to introduce themselves while you’re going to start a conversation.

Therapy and rehabilitation are key to helping you adapt to this condition if it’s permanent. You may learn techniques and strategies from primary healthcare professionals. They will help you to cope up with any kind of agnosias & make your life more blissful.



  1. How Common Is Face Blindness? (2023, February 24). Harvard Medical School.,for%20face%20blindness%2C%20or%20prosopagnosia.
  2. Schultz RR, Bertolucci PH. Congenital prosopagnosia: A case report. Dementia & Neuropsychologia. 2011 Jan;5:54-7.
  3. Prosopagnosia. (n.d.). National Institute of Neurological Disorders and Stroke.,a%20genetic%20mutation%20or%20deletion.
  4. Professional, C. C. M. (n.d.). Agnosia. Cleveland Clinic.,that%20it’s%20the%20same%20picture.
  5. Kawamura M, Sugimoto A, Kobayakawa M, Tsuruya N. Neurological disease and facial recognition. Brain and Nerve= Shinkei Kenkyu no Shinpo. 2012 Jul 1;64(7):799-813.

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