dysmetropsia

Dysmetropsia is a perceptual distortion in which familiar objects are mismeasured in size, distance, or scale. It is a form of metamorphopsia focused on the perception of magnitude and can include macropsia (perceived enlargement), micropsia (perceived reduction), or mislocalization of objects in space.

Symptoms typically involve seeing objects larger or smaller than they are and misjudging their distance or depth. The effect may affect one or both eyes and can be transient or persistent. Dysmetropsia may occur in the context of other visual disturbances, such as blurring, scotomas, or aura features in migraine.

Causes are diverse and often relate to neurological or ocular pathology. Neurological conditions associated with dysmetropsia include migraine with aura, seizures, stroke, tumors, or other focal lesions in the occipital or parietal cortex. Ocular or retinal diseases can contribute to metaplastic distortions when the central retina or macula is affected, though dysmetropsia is most commonly discussed in relation to cortical processing. Certain medications or intoxication can also influence visual perception.

Diagnosis requires a careful history and targeted examination by neurology and ophthalmology. Neuroimaging is used if a neurological cause is suspected, while retinal imaging and examination address potential ocular contributors. Management focuses on treating the underlying condition, with migraine therapies for aura-related cases and ophthalmologic or neurologic interventions as indicated. Prognosis varies with the etiology and response to treatment.