Conjunctival Argyrosis
Argyrosis of the conjunctiva is a rare ocular condition in which silver particles deposit in the conjunctival tissues, producing a gray-blue or brown-black discoloration of the bulbar and palpebral ...
Rx Eye & Vision Care (A – Z)
Argyll Robertson Pupils
Argyll Robertson pupils are an uncommon but highly specific ocular sign characterized by small, irregular pupils that do not constrict in response to bright light, yet do constrict normally when ...
Argentinian Flag Sign (AFS)
The Argentinian Flag Sign (AFS) is an intraoperative complication encountered during cataract surgery, most notably when performing a manual continuous curvilinear capsulorhexis (CCC) on an ...
Arcus Senilis
Arcus senilis is a gray-white or bluish ring that appears around the outer edge of the cornea, the clear “window” at the front of your eye. This ring is formed by lipid (fat) deposits in the ...
Aqueous Misdirection
Aqueous misdirection is a rare form of secondary angle-closure glaucoma in which the normal flow of the eye’s clear fluid (aqueous humor) is disrupted. Instead of moving forward through the pupil ...
Apraxia of Eyelid Opening (ALO)
Apraxia of Eyelid Opening (ALO) is a non-paralytic motor disorder in which a person cannot initiate the voluntary act of lifting the upper eyelid after it has been closed, despite normal eyelid ...
Generalized Eyelid Edema
Generalized eyelid edema, also known as periorbital or bilateral eyelid swelling, is the accumulation of excess fluid within the loose connective tissues of one or both eyelids. This fluid buildup ...
Aponeurotic Ptosis
Aponeurotic ptosis, also called involutional or senile ptosis, is characterized by a drooping of the upper eyelid due to weakening, dehiscence, or disinsertion of the levator palpebrae superioris ...
Apocrine Hidrocystoma
Apocrine hidrocystoma is a benign, fluid-filled cyst that arises from the apocrine sweat glands, which are specialized glands most numerous in areas such as the eyelids, armpits, and groin. These ...
Aphantasia
Aphantasia is a neurological condition where a person cannot voluntarily create mental images in their mind. Imagine closing your eyes and trying to picture a loved one’s face or a bright red ...
Anton Syndrome
Anton Syndrome, also called Anton–Babinski syndrome or visual anosognosia, is a rare neurological condition in which a person with cortical blindness adamantly denies their vision loss and often ...
Retrograde Degeneration in the Optic Pathway
Retrograde degeneration in the optic pathway refers to the process whereby damage to neurons farther along the visual tract causes progressive injury “upstream,” toward the eye itself. This ...
Anterograde (Wallerian) Degeneration
Anterograde (Wallerian) degeneration is the process by which the section of a nerve fiber (axon) beyond the point of injury breaks down and is cleared away. In this active, self-destructive sequence, ...
Anterior Stromal Puncture
Anterior stromal puncture (ASP) is a minor surgical procedure used to treat recurrent corneal erosion (RCE) syndrome. In this technique, tiny punctures are made through Bowman’s layer into the ...
Anterior Segment Trauma
Anterior segment trauma refers to any injury affecting the front structures of the eye, namely the cornea, conjunctiva, anterior chamber, iris, ciliary body, and crystalline lens. This region, ...
Anterior Segment Optical Coherence Tomography for Ocular Surface Lesions
Anterior Segment Optical Coherence Tomography (AS-OCT) is a noninvasive imaging technique that uses light waves to capture high-resolution cross-sectional images of the front part of the eye. By ...
Anterior Segment Optical Coherence Tomography Features of Keratitis
Anterior Segment Optical Coherence Tomography (AS-OCT) is a noninvasive imaging technology that captures high-resolution cross-sectional images of the eye’s anterior structures, including the cornea, ...
Anterior Segment Optical Coherence Tomography (AS-OCT)
Anterior Segment Optical Coherence Tomography—often shortened to AS-OCT—is a non-contact, light-based imaging test that lets eye-care professionals see microscopic cross-sections of the cornea, ...
Anterior Segment Developmental Anomalies
Anterior segment developmental anomalies (ASDAs), also known as anterior segment dysgenesis (ASD), comprise a spectrum of congenital disorders in which one or more of the front structures of the ...
Anterior Chamber-Associated Immune Deviation (ACAID)
Anterior Chamber-Associated Immune Deviation (ACAID) is an active, antigen-specific form of immune tolerance induced when an antigen is introduced into the anterior chamber of the eye. Rather than ...
