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Macropsia, also known as megalopia, is one of the neurological disorders that affects a person’s visual perception. This particular neurological condition causes people to see things bigger than they really are. It can be caused by illegal drug use, prescription medications, migraines, or epilepsy. Retinal problems can also be a cause.
The retina is an important part of the eye. Light enters the eye and is picked up by the retina and its photoreceptor cells. These nerve cells convert the light into pulsating electrical signals that travel through the optic nerve. From this point, the signals reach the brain and are converted into images. Macropsia alters how images are perceived because the photoreceptor cells, called cones, are compressed which makes the brain perceive things in larger sizes.
There are many different neurological problems that can cause macropsia as a symptom. Alice in Wonderland syndrome (AIWS) and aniseikonia are common problems. Particularly extreme forms of migraine headaches can lead to vision disturbances. Rarely, complex partial seizures can cause episodes of visual changes.
Aniseikonia is a form of macropsia that only affects one eye instead of both eyes. In this instance, defects in the structure, particularly in the retina, cause one eye to perceive objects larger while the other eye functions normally. Epiretinal membrane is one disease that can lead to aniseikonia. Changes in the vitreous humor cause damage to the retina.
AIWS, also known as Todd’s syndrome, can cause macropsia or micropsia, which is a condition that causes people to see things smaller than they really are. This syndrome is generally temporary. It often occurs in conjunction with migraine attacks or tumors in the brain.
Prescription medicines, such as those used to treat insomnia and depression, can be another cause of macropsia. These, and many other types of prescriptions, have side effects that can alter visual perception. To avoid recurring disturbances in vision, doctors may change dosage amounts periodically.
Migraine headaches are a common cause of many different types of vision problems, including macropsia and micropsia. The peak of a migraine causes neurological interruptions. Many sufferers notice that they have visual distortion in addition to auditory distortion and heightened sensitivity to light, sound, and touch. These visual changes subside after the migraine attack has passed.
Complex partial epilepsy causes seizures that allow the sufferer’s vital signs to remain normal so as to not lose consciousness. These seizures can also cause visual and auditory problems. It is a rare instance for macropsia to occur as a symptom of epilepsy.