The lack of visual perception. The decline in vision can occur gradually or abruptly, and its duration may vary, ranging from temporary to permanent, contingent on the underlying reasons. Visual impairment can impact a single eye or both eyes and might lead to total blindness or exclusively affect peripheral or central vision.
The decline in vision quality is often associated with aging and can result from various conditions.
A sudden decrease in eyesight could be due to various medical conditions, such as hyphaema, which involves bleeding into the eye’s aqueous humor, or severe uveitis, an inflammation of the iris or choroid. Other causes might include vitreous hemorrhage, which is bleeding into the eye’s internal gel, retinal hemorrhage, or optic neuritis, an inflammation of the optic nerve that usually affects vision in one eye.
Impairment to the neural pathways connecting the eyes and brain, or damage to the brain’s visual region, can lead to a loss of peripheral vision. Such nerve damage can stem from various conditions like embolism, ischaemia, tumors, inflammation, or physical injury.