Vision loss

Vision loss or visual loss is the absence of vision where it existed before, which can happen either acutely (i.e. abruptly) or chronically (i.e. over a long period of time).

Planum sphenoidale (PS) and tuberculum sellae (TS) meningiomas cause visual symptoms due to compression of the optic chiasm.

see Planum sphenoidale meningioma.

see Tuberculum sellae meningioma.

Optic pathway gliomas (OPG) represent an important cause of visual loss in pediatric population., is a decreased ability to see to a degree that causes problems not fixable by usual means, such as glasses.

Some also include those who have a decreased ability to see because they do not have access to glasses or contact lenses.

Visual impairment is often defined as a best corrected visual acuity of worse than either 20/40 or 20/60.

The term blindness is used for complete or nearly complete vision loss.

Visual impairment may cause people difficulties with normal daily activities such as driving, reading, socializing, and walking.

see Visual impairment

There are many types of eye problems and vision disturbances, such as:

Monocular vision loss

Halos

Blurred vision (the loss of sharpness of vision and the inability to see fine details)

Blind spots or scotomas (dark “holes” in the vision in which nothing can be seen)

Loss of vision is considered sudden if it develops within a few minutes to a couple of days. It may affect one or both eyes and all or part of a field of vision. Loss of only a small part of the field of vision (for example, as a result of a small retinal detachment) may seem like blurred vision. Other symptoms, for example eye pain, may occur depending on the cause of vision loss.

Sudden loss of vision has three general causes:

Clouding of normally transparent eye structures Abnormalities of the retina (the light-sensing structure at the back of the eye) Abnormalities of the nerves that carry visual signals from the eye to the brain (the optic nerve and the visual pathways) Light must travel through several transparent structures before it can be sensed by the retina. First, light passes through the cornea (the clear layer in front of the iris and pupil), then the lens, and then the vitreous humor (the jellylike substance that fills the eyeball). Anything that blocks light from passing through these structures, for example, a corneal ulcer or bleeding into the vitreous humor, can cause loss of vision.

Most of the disorders that cause total loss of vision when they affect the entire eye may cause only partial vision loss when they affect only part of the eye.

Patients with severe visual impairment were found to have bad outcomes. The visual symptoms related with increased intracranial pressure should be carefully monitored and controlled to improve outcomes ¹⁾.