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Scintillating scotoma is a common visual aura that was first described by 19th-century physician Hubert Airy (1838–1903). Originating from the brain, it may precede a migraine headache, but can also occur acephalgically (without headache), also known as visual migraine or migraine aura. [4]
Ophthalmology. Illusory palinopsia is a subtype of palinopsia, a visual disturbance defined as the persistence or recurrence of a visual image after the stimulus has been removed. [1] Palinopsia is a broad term describing a heterogeneous group of symptoms, which is divided into hallucinatory palinopsia and illusory palinopsia. [2]
It results in halos around point images. Spherical aberration exacerbates myopia in low light (night myopia). In brighter conditions, the pupil constricts, blocking the more peripheral rays and minimizing the effect of spherical aberration.
At the early stage, a retinal hemorrhage may not show any symptom at all. Some symptoms may include: Seeing floaters in the vision. Seeing cobwebs in the vision. Seeing haze or shadows. Distorted vision. Rapid flashes of light in peripheral vision. Red tint to vision. Blurriness.
Tunnel vision is the loss of peripheral vision with retention of central vision, resulting in a constricted circular tunnel-like field of vision.
Peripheral vision, or indirect vision, is vision as it occurs outside the point of fixation, i.e. away from the center of gaze or, when viewed at large angles, in (or out of) the "corner of one's eye". The vast majority of the area in the visual field is included in the notion of peripheral vision.
Phosphene. An artist's representation of how some people may see phosphenes by retinal stimulation. A phosphene is the phenomenon of seeing light without light entering the eye. The word phosphene comes from the Greek words phos (light) and phainein (to show).
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Acute angle closure glaucoma, a medical emergency due to the risk of impending permanent vision loss, is characterized by sudden ocular pain, seeing halos around lights, red eye, very high intraocular pressure, nausea and vomiting, and suddenly decreased vision.
Closed-eye hallucinations and closed-eye visualizations ( CEV) are hallucinations that occur when one's eyes are closed or when one is in a darkened room. They should not be confused with phosphenes, perceived light and shapes when pressure is applied to the eye's retina, or some other non-visual external cause stimulates the eye.