Diminished visual brightness is a condition where eyes perceive objects as darker and colors less vibrant than usual, despite adequate ambient light. For instance, while observing a field of flowers, a person with normal vision sees bright, vivid colors. Conversely, with diminished visual brightness, colors may appear faded, less lively, or certain areas within the visual field might turn gray. Below are several potential causes of this condition.

Optic neuritis

Optic neuritis is an inflammation of the nerve fibers that transmit signals from the retina to the brain, leading to reduced visual brightness. The degree of impairment depends on the extent of nerve fiber damage. Common symptoms include blurry vision (often in one eye), faded or dull colors, and pain behind the eyeball, especially with eye movement. Vision may worsen after strenuous activity or hot baths.

Diagnosis primarily relies on clinical examination and magnetic resonance imaging (MRI). The condition can resolve on its own, but severe cases require strict adherence to doctor's instructions to shorten recovery time.

Amblyopia

Amblyopia, or "lazy eye," is a condition where one eye has poorer vision than the other, typically developing early in life. Causes include severe refractive errors, strabismus, cataracts, ptosis, or corneal damage. Since the brain favors the stronger eye, the weaker eye does not fully develop its visual function. Early detection and treatment, such as patching the stronger eye to train the weaker one, eye drops, or special glasses, can be beneficial.

Macular degeneration

Macular degeneration has two forms: dry and wet. The dry form progresses slowly, characterized by the accumulation of drusen—small, yellow deposits of fat and protein—in the macula region of the retina. This accumulation reduces visual brightness, making it difficult for patients to read and perceive colors as vibrantly. As the early stages often present with few or no clear symptoms, regular eye examinations are crucial for early detection and monitoring of the disease.

Retinal detachment

Retinal detachment occurs when the light-sensitive tissue layer separates from the back of the eyeball. Warning signs include a fixed shadow in the field of vision, flashes of light, floaters, or sudden loss of peripheral vision. This is an emergency condition requiring prompt treatment.

Glaucoma

Glaucoma is a disease causing progressive optic nerve damage, often silently in its early stages. In advanced stages, patients may experience blurry vision as if through a fog, see halos around lights, or suffer sudden vision loss. Regular eye exams help detect it early through intraocular pressure measurement, fundus examination, and visual field testing. Treatment aims to slow progression with medication, laser, or surgery, but cannot restore lost vision.

Cataract

Cataracts cause the eye's natural lens to become cloudy, reducing clarity and brightness of vision. Patients may experience blurred vision, light sensitivity, difficulty seeing at night, or double vision. Diagnosis is made through a dilated eye exam. Artificial lens replacement surgery is indicated when the condition impacts daily activities.

Brain tumor

A brain tumor can cause vision impairment depending on its location, accompanied by signs such as visual field loss, double vision, or optic nerve swelling. Associated neurological symptoms include headaches, seizures, memory impairment, or sensory changes. Treatment may involve surgery, monitoring, radiation therapy, or chemotherapy, depending on the tumor type and stage.

Bao Bao (According to Very Well Health)