A blind spot, scotoma, is an obscuration of the visual field. Conditions of glare, partial obscuration, rain, snow, fog, and darkness all compound the problem. Glass bricks provide visual obscuration while admitting light. If light blocking (obscuration) is used the loss of light is detected. It does not require obscuration by dust. Obscuration and moment of time with maximum magnitude (UTC) are indicated. With smoke obscuration, a rush might have succeeded but the distance was impossible. Parts of the western Antarctic Peninsula experienced nearly 90% obscuration of the Sun. They include a rapid obscuration system (ROSY), laser warning system and acoustic shot locator system. Obscuration of the nasal border of the disc. For big cities in Russia, the maximal obscuration was in Anadyr, and it was 27.82%. The obscuration of this life disappeared in a fragile dawn of prenatal memories. Rare obscuration of a major blood vessel, usually on the upper pole. This produces a very effective obscuration per weight of material used. Obscuration of one or more segments of major blood vessels leaving the disc.