Table 1.

Main visual system alterations in neurodegenerative diseases.

Alzheimer Disease	Parkinson Disease
Visual acuity reduction	Visual acuity reduction
Visual field alterations	Visual field alterations
Color discrimination impairment	Color discrimination impairment
Electrophysiology alterations	Eye movements function deficits
Contrast and temporal discrimination impairment	Pupil function and reactivity decreases
Visual and visuo-motor tasks alterations	Electrophysiology alterations
Visual hallucinations	Contrast and temporal discrimination impairment
Posterior pole morpho-functional alterations	Visual and visuo-motor tasks alterations
Balint’s syndrome (simultanagnosia + ocular motor apraxia + optic ataxia)	Visual hallucinations
Corneal nerves alterations	Corneal nerves alterations
Retinal and optic nerve morpho-functional alterations	Retinal and optic nerve morpho-functional alterations
Intracranial visual system morpho-functional changes	Intracranial visual system morpho-functional changes