Metamorphopsia: types, symptoms and treatment

Perception is the ability of human beings to capture information from the surrounding environment, which after being processed allows us to react and adapt to the environment. Capturing this information is vital for survival and largely depends on our sense organs.

However, sometimes our senses deceive us and perceive something that does not exist, or they perceive something with characteristics that stray from reality. For this last hypothesis remains the phenomenon known as metamorphopsia.

    The concept of metamorphopsia

    It is understood as metamorphopsia a a type of perceptual alteration in which the suffering subject grasps the size or shape of objects differently from what they really are. This type of perceptual alteration occurs at the visual level and is linked to the perception of distances.

    It is a real perception of a stimulus which really exists, although the object is perceived with characteristics which differ from the real ones. Metamorphopsia is therefore a type of perceptual distortion, In which a specific stimulus or stimuli is perceived abnormally. In this way, we are not dealing with content that can be called perceptual deception: it is not a hallucination.

    As a rule, the subject who undergoes some type of metamorphopsia is able to detect that his perception is distorted, and is aware that the shapes or sizes detected are not correct. It can cause a high level of stress and anxiety before it appears.

    Metamorphopsia is not a disorder in itself, but is considered a symptom from which it can infer the existence of a medical or psychological problem. It is not a dangerous condition in itself, although it can be annoying and it can lead to wrong judgments about reality. However, depending on the case, the problem causes it if it can be of some seriousness.

      Appearance of this alteration

      Metamorphopsia it is a perceptual distortion that can appear under very different conditions, For both biological and psychic causes.

      It frequently appears before alterations in the brain nuclei responsible for vision, as well as before parietal lobe epilepsy or brain tumors. Of the same, trauma, stroke, intracranial hemorrhage, and other types of brain damage they can also cause it.

      The eye and retina are also often key points in the development of disorders that cause metamorphopsia to appear. It is common to appear with macular degeneration, Retinal fractures, retinal vein infarction, edema related to age or even in some cases as a result of diabetes, extreme myopia or inflammation resulting from surgeries.

      Another factor linked to the appearance of metamorphopsia is the consumption of substances with psychoactive properties, and the appearance of this symptom is frequent when faced with the consumption of hallucinogens such as LSD or mescaline, narcotics or even in the face of certain psychotropic drugs.

      Sometimes they can occur due to states of intense emotional activation like terror, anguish or anger. Although it can appear in some mental disorders, it is not uncommon. In the latter case, the disorder called Alice in Wonderland syndrome stands out.

      Different types of metamorphosis

      Metamorphopsia is a perceptual distortion that can be found in which different types of sensory alterations can appear. Generally speaking, we can find three main types of metamorphopsia.

      1. Dysmegalopsia

      It is a type of metamorphopsia in which alteration occurs in the absorption or perception of the size of the stimulus. If our perception of the stimulus is larger than its actual size, we are talking about a macropsia.So that if we perceive something to be smaller than it is, we are talking about a micropsy.

      2. Dysmorphopia

      Dysmorphopsia is understood as a type of metamorphopsia in which the aspect that is perceived to be distorted is the shape of the stimulus in question. The most common is to see deformed objects or people, As with ripples.

        3. Self-metamorphosis

        Another type of metamorphopsia is found in autometamorphopsia, in which we perceive our own body in an abnormal way.

        4. Reverse metamorphosis

        This type of metamorphopsia is not very common. In this case, it is not the form neither the size of what looks distorted, but the spatial location. This way we can see things reversed, as if we are hanging upside down or in other different orientations.


        Because it is a symptom and not a disorder in itself, the choice of which treatment or therapy to use will depend largely on the disease that generates it. In general, the visual system should be checked to see if the perception problem is due to visual or neurological alterations, as well as if the subject has consumed psychoactive substances or is in some type of pharmacological treatment.

        also provide information to the subject about what is happening to him it is fundamental, because perceptual and especially visual alterations often elicit a certain level of panic and anxiety in addition to uncertainty as to why they see this way.

        Bibliographical references:

        • Belloch, A., Bains, R. and Perpiñá, C. (2008) Psychopathology of perception and imagination. In A. Belloch, B. Sandín and F. Ramos (Eds.) Handbook of Psychopathology (2nd edition). Vol I, Madrid: McGraw Hill Interamericana.
        • Sants, JL (2012). Psychopathology. CEDE PIR preparation manual, 01. CEDE. Madrid.

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