Troxler's fading, also called Troxler fading or the Troxler effect, is an optical illusion affecting visual perception. When one fixates on a particular point for even a short period of time, an unchanging stimulus away from the fixation point will fade away and disappear.
This is a symptom of a variety of conditions, including amblyopia, optic neuritis, retinal detachment, macular degeneration, glaucoma, cataracts, or brain tumor. If you note dimness of vision, see an ophthalmologist to have the problem diagnosed and treated.
It's called the Troxler Effect, named after Ignaz Paul Vital Troxler, a Swiss physician who discovered the phenomenon more than 200 years ago. He noticed that when he made himself stare at a central point of an image, objects in his peripheral vision started to disappear within seconds.
Visual snow, or visual static, is an uncommon neurological condition that affects around 2% of the population.
Visual snow may occur even years after hallucinogenic drug use, and even after only one time use. There may be a family history of visual snow or migraine. Investigations into scotopic sensitivity syndrome have identified similar features in ADHD, dyslexia, and chronic fatigue syndrome.
Initial functional brain imaging research suggests visual snow is a brain disorder. Visual snow is a chronic condition, sometimes highly disabling, uncommon condition that is in need of collaborative research and lateral thinking to make progress towards understanding, treatment and cure.
In normal observers, gazing at one's own face in the mirror for a few minutes, at a low illumination level, produces the apparition of strange faces. Observers see distortions of their own faces, but they often see hallucinations like monsters, archetypical faces, faces of relatives and deceased, and animals.
Peduncular hallucinosis (PH) is a rare neurological phenomenon that causes vivid visual hallucinations that typically occur in dark environments and last for several minutes.
Nyctanopia; Nyctalopia; Night blindness. Night blindness is poor vision at night or in dim light. The cornea allows light to enter the eye. As light passes through the eye the iris changes shape by expanding and letting more light through or constricting and letting less light through to change pupil size.
Amaurosis fugax refers to a temporary black-out of vision. This is usually affects one eye, is painless, and is often described like a "shade coming down over the vision" of that eye. The black-out may last minutes, and then the vision returns.
Finally, severe anxiety can make you feel dizzy, which may make you feel like your vision has become blurred. In the long term, when extreme stress and anxiety happens frequently, your body's heightened cortisol levels can cause glaucoma and optic neuropathy, which can lead to blindness.
Fluctuating vision may be a sign of diabetes or hypertension (high blood pressure), which are chronic conditions that can damage the blood vessels in the retina. Any damage to the retina can cause permanent vision loss, and so a patient with fluctuating vision should seek immediate medial attention.
If you struggle to see while you're driving at night – or can't see at all, or if you're sitting in a barely lit restaurant and you can hardly see, you might have night blindness. See your healthcare provider right away because night blindness can be a symptom of a serious disease.
Once you hit your 50s, aging brings a gradual reduction in the size of the pupil (so less light hits the retina) and a decrease in the number of rods in the retina (the cells that control twilight-and-night vision). Contrast sensitivity is also reduced, which makes it more difficult to discern objects in the dark.
Results indicate that the period of susceptibility to darkness extends only to about 10 weeks of age, which is substantially shorter than the critical period for the effects of monocular deprivation in the primary visual cortex, which extends beyond six months of age.
You may have hallucinations if you: hear sounds or voices that nobody else hears. see things that are not there like objects, shapes, people or lights. feel touch or movement in your body that is not real like bugs are crawling on your skin or your internal organs are moving around.
It Can Disturb Sleep
Having a mirror facing the bed can disturb your sleep, especially if you're sensitive to light. Even if the room is dark, any light reflected off the mirror can cause discomfort and prevent you from falling asleep or staying asleep. It could also give you the impression that you are being watched.
The Irish wake is a well-known funeral tradition where the family of the deceased covers all mirrors in the home. To hide the physical body from the soul, the family turns mirrors to face the wall. Some Irish superstitions say that if you look in a mirror long enough, you'll see a devil looking over your shoulder.
“The creepiness is probably tied to the way in which a mirror creates a duplicate world—when you look in a mirror, you're always seeing something that's not actually there,” says Phillips.
Visual snow syndrome is a rare neurological condition that causes static-like dots to appear in your field of vision. It can also sometimes occur during times of stress and anxiety, but not for everyone. Visual snow syndrome is a rare condition that causes disturbances in a person's vision.
Visual snow syndrome (VSS) is a relatively rare, unusual and enigmatic medical condition [1–4]. It frequently occurs in patients with concussion/mild traumatic brain injury (C/mTBI) and other brain-related abnormalities [1–7]. VSS presents with a constellation of visual and non-visual problems.
Anxiety can cause tunnel vision and visual snow; and perhaps other visual spots as well. In addition, floaters, tunnel vision and visual snow can cause you to become worried, anxious and hypervigilant because you think they are a symptom of a serious eye problem.
Vitamin A plays an important role in your vision. To see the full spectrum of light, your eye needs to produce certain pigments for your retina to work properly. Vitamin A deficiency stops the production of these pigments, leading to night blindness.