6 articles
Afterimage
Afterimage: a visual illusion in which an image persists after the stimulus is removed; positive (same color) or negative (complementary color) forms, retinal and cortical mechanisms, Emmert's law, and clinical afterimage testing.
Contrast (vision)
Contrast in vision is the difference in lightness or darkness between an object and its background; contrast sensitivity testing can detect eye diseases that standard acuity measurement misses.
Dark Adaptation
Dark adaptation is the slow recovery of visual sensitivity in darkness after light bleaches rhodopsin, taking 30–40 minutes, driven by the retinoid cycle, and delayed in AMD, where rod intercept time is a clinical biomarker.
Eigengrau
Eigengrau (Eigenlicht, dark light, brain gray) is the intrinsic dark gray seen in total darkness, a term credited to Gustav Fechner, caused by spontaneous retinal dark noise from visual pigment and phototransduction fluctuations.
Night vision
Night vision: low-light seeing mediated by rod photoreceptors and rhodopsin, restored through slow dark adaptation and the RPE visual cycle; vitamin A deficiency, Oguchi disease, and AMD delay it.
Tapetum lucidum
Tapetum lucidum: reflective layer behind the retina of many vertebrates and some invertebrates that boosts dim-light vision and causes eye-shine; types include retinal, guanine, cellulosum, and fibrosum tapeta; absent in primates, birds, and pigs.