Life, eye disease and work of Joseph Plateau.

The Belgian physicist Joseph Plateau (1801-1883) suffered from uveitis which made him blind at the age of 42 years and which has been ascribed to a previous solar retinitis. Plateau described many visual phenomena, including the persistence of visual impressions. He invented instruments which foreshadowed the cinema.

On the poor legibility of the captions in musea.

In the museum world, designers in general hardly take into account the legitimate wishes of elderly visitors, whose visual acuity is often less than optimal, with regard to the legibility of the captions by paintings or in show-cases. The conditions necessary for letter and word recognition, the influence of illumination, contrast and colour are discussed. Test-cards for use in musea, and the recruiting of a representative test-group of senior citizens, are recommended.

Inter- and intraindividual sensitivity variations with manual and automated static perimeters.

Increment sensitivities in the monocular visual field were determined once in 10 different normal subjects by means of the Octopus, Humphrey, Perimat and Tübingen perimeters and 10 times in one single normal subject. Interindividual spread was greater than intraindividual spread; the spread augmented towards the periphery and in the superior quadrant of the visual field and was generally greater in automated perimetry than in manual Tübingen perimetry, especially in the region of the blind spot. Thus in our experience automated perimetry is not more precise than manual Tübingen perimetry in normal subjects.

Modification by fluoangiography of color vision in diabetic patients.

Fluoangiography causes in diabetics a temporary increase of the number of errors when reading Birch and SPP II pseudoisochromatic plates, especially in case of macular edema and for tritan plates. Other experiments show that this change is more due to an increased filter effect by the fluorescein accumulation than to the increase of glare by the flashes for photography. Measurements of the foveal spectral increment threshold sensitivity curves does not show impairment of the blue mechanism by fluoangiography; on the contrary the green and red mechanisms become less sensitive.

[Lanthony's New Color Test. V. Classification of the grays]. / Le New Color Test de Lanthony. V. Classement des gris.

It is easy to make a shortened Lightness Discrimination Test (LDT) using the grey caps of the New Color Test (NCT). The shortened test shows the reduction in contrast sensitivity as well as the original LDT in squint amblyopia multiple sclerosis, optic neuritis and cerebral tumours. So it is a useful complement to the NCT.

Muscular activity and perimetric thresholds.

Static and kinetic peripheral luminance thresholds were measured by means of a Goldmann perimeter along oblique meridians in monocular vision. In a main group of 33 young and healthy subjects these measurements and visual reaction time assessments were made successively at rest, when cycling without load, when cycling with load using aerobic energy supply, when cycling with load using anaerobic energy supply and twice again at rest. Another group of subjects did not pedal and served as controls. The results show that peripheral visual sensitivity increases faintly but significantly during muscular exercise. When assessed by static perimetry the sensitivity increase is grossly proportional with load and is thus greatest in anaerobic condition, while kinetic sensitivity differs by a sensitivity decrease when passing from aerobic to anaerobic exercise. The reported modifications in perimetric sensitivity during dynamic muscular exercise seem related to changes in alertness.