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Fifteen patients with retinitis pigmentosa (RP) were examined with a non-Maxwellian view system developed by Kulikowski and Carden. The patients included those having autosomal recessive, autosomal dominant and simplex inheritance patterns. Their visual acuity ranged from 0.1 to 1.0. Achromatic (25 Hz) and chromatic (1 Hz) thresholds were measured at different wavelengths from 400 to 640 nm in 200 nm steps with central fixation. RP patients showed significant sensitivity losses for both achromatic and chromatic stimulus conditions. Achromatic sensitivity losses were similar at all wavelengths, but chromatic sensitivity losses were greatest at short wavelengths, intermediate at long wavelengths and least at middle wavelengths.

The aim of this study was to develop a computer-based test for colour vision deficiencies. In order to compare colour stimuli of standard tests with colour stimuli of a VDU, we compared the gamut of our VDU to the chromaticity coordinates of standard tests. We also implemented the Farnsworth D-15 test and one plate from the Ishihara Pseudo-Isochromatic Plates on the colour VDU. The results showed that a colour VDU might be a useful device for studies on colour vision deficiencies.

Spectral and flicker sensitivity functions were measured for 20 normal, well-trained subjects using the non-Maxwellian view system of Kulikowski and Carden. Foveal thresholds were determined at 1 Hz and 25 Hz presentation rates in 20 nm steps from 400 to 640 nm, using a 32’ angular diameter test stimulus superposed on a 15° concentric white background of 10 cd/m2.

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.

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.

Energetical achromatic increment thresholds on a white background of 10 cd.m−2 were determined at 5 eccentricities by means of 8 interference filters in corporated to a calibrated Tubingen perimeter.

New extentive experiments demonstrated that: (a) protan observers are more deficient than deutan ones with regard to perception distances of some traffic panels, of vehicle red stop lights, of vehicle red rear-position lights and of white, yellow and red reflectors. Contrarily, deutan observers are more deficient than protan ones for the distinction of differently coloured traffic lights and vehicle rear lights; (b) protan and deutan drivers are nevertheless not responsible for more traffic accidents than drivers with normal colour vision; (c) this apparent contradiction is due to psychological compensation mechanisms. The practical conclusions are: (a) that persons with defective colour vision need not to be excluded from non professional road traffic; (b) that it is nevertheless useful that they should be aware of their handicap; (c) that the red traffic signal has to be larger than the other ones; and (d) that the stop and red position lights of vehicles must be sufficiently intense and that the filters transmitting only pure red should be avoided in them.

The responses at the Ishihara test, the Nagel anomaloscope, the standard Panel D--15 and the 100 hue test (with correction of the age effect) were recorded in 38 alcoholics in deprivation period (successively subdivided according to age, to abstinence duration and to liver condition) and in 32 subjects suffering from mental diseases (successively subdivided according to ethylic past, to age, to duration of the stay in the hospital and to activity). It is shown that alcoholism causes a diminution of the performance at the used colour vision tests and especially at the 100 hue test. The defect can be ascribed to psychical factors (chiefly in the cases of mental disease and in the younger people), but also to an acquired blue-yellow defectiveness of colour vision with a shift of the Rayleigh match to red (such a defectiveness can also be due to a liver damage and to some intoxications) and even to a Type II acquired red-green defectiveness of colour vision (possibly by tobacco or disulfiram intoxication). The defect due to alcohol itself soon disappears during desintoxication. The authors draw some practical conclusions.

The combination of a light source of variable intensity with an optocinetic drum and with an electronystagmographic apparatus allows the quantitative evaluation of dark adaptation simultaneously in a subjective way and an objective way. Our principal series of measurements concerns 60 human subjects, subdivided in 4 classes of ages ranging from 2 1 2 to 29 years; it clarifies the relationship between the subjective and objective thresholds, and also indicates that the thresholds are lowest at the end of the second decade of life; in the younger subjects, all thresholds are higher and the adaptation speed is smaller in the photopic segment of the curve.

Sixteen abstinent and 24 moderately drinking male subjects have been submitted twice to an elaborate and standardized test run, involving measurements of threshold luminance during the course of dark adaptation, during glare in the dark adapted state, and after glare in the dark adapted state; measurements of threshold luminance for ten visual acuities belonging to the scotopic and mesopic ranges; and measurements of the pupillary diameter under photopic conditions. In every subject of each group one test run was done under control conditions, and the other after an alcohol ingestion giving rise to a blood alcohol concentration of about 0·065%. The great majority of the paired mean results obtained in this way do not differ significantly, so that our experience contradicts other authors' statements claiming an obvious visual disturbance from blood alcohol concentrations as low as 0·045%. However, the few significant differences we obtained suggest that the resistance to glare is slightly diminished in a very late stage, and that abstinent subjects might be more prone to sustain their performance by an increase of vigilance.

Resume A l'aide d'un banc d'optique, de filtres interferentiels et d'un photometreapapillotement de Bechstein, presentant un champ d'observation de 1° 30′ entoured'un champ peripherique d'adaptation de 30° et de meˆme luminance, nous avons determine,adeseclairements retiniens de 55 et de 415 trolands, des courbes spectrales iso-energetiques d'efficacitelumineuse relativeacelle d'une radiation de 552 nm chez 25 sujets protanopes, 23 protanomaux, 24 deuteranopes, 27 deuteranomaux, sept achromates typiques et un achromate atypique du type “blue mono-cone monochromacy”. Le materiel de comparaison est constituepar un groupe de 25 sujets normaux de meˆmeaˆge moyen. Tous les groupes de sujets anormaux presentent des courbes moyennes tres significativement differentes de celle du groupe de sujets normaux. Les groupes protan ont des facteurs moyens augmentes en decade 552 nm et diminues au-delade 552 nm, tandis que les groupes deutan ont des facteurs moyens diminues en decade 552 nm et augmentes au-delade 552 nm. Par contre, il n'y a que des differences minimes et non-significatives entre la fonction moyenne d'un dichromatisme et celle du trichromatisme anormal correspondant. La comparaison entre les deux niveaux d'eclairement retinien montre que le “phenomene inverse de Purkyne” des sujets normaux est retrouvechez les sujets deutan et retrouvepartiellement chez les sujets protan. La dispersion des valeurs individuelles au sein des groupes protan et deutan n'est jamais plus petite que la dispersion normale ; celle parmi les sujets protan est particulierement grande entre 567 et 641 nm et celle parmi les sujets deutan est particulierement grande entre 489 et 567 nm. Toutefois, les trichromates anormaux ne presentent pas de correlation significative entre le quotient d'anomalie et les facteurs pour 489 et 616 nm. Ce n'est que chez un achromate typique et au seul niveau de 55 trolands que la courbe coincide convenablement avec la fonction scotopique V ′(λ) de la C.I.E.; chez les autres achromates typiques l'accord n'est obtenu que si la fonction V ′(λ) est corrigee pour une absorptiona50 pour cent de la pigmentation maculaire normale. Ce meˆme resultat est donnepar l'achromate atypique au niveau de 55 trolands, tandis que celui de 415 trolands donne une fonction “bleue” culminanta450 nm. Apres une legere correction faisant coincider la courbe moyenne de nos sujets normaux avec la fonction photopique V (λ) de la C.I.E., nous avons calculeune fonction moyenne protan V p (λ), un peu differente de la fonction W p de Judd, ainsi qu'une fonction moyenne deutan V d (λ).

Some three-quarters of a century ago the various forms of acquired colour vision deficiencies had already been well studied by Koenig, von Kries, Koellner, and other German scientists using spectral devices. However, these studies have been greatly neglected, and it is only within the last few years that there has been a renewed interest in this field, of which the first approach has been greatly facilitated in the meantime by the Panel D-15 and the 100-Hue of Farnsworth . Generally speaking, nearly all ocular diseases give rise to absorption systems, while lesions in the deeper layers of the retina elicit a predominant reduction of the blue-yellow sense, and lesions in the ganglion layer and in the optic nerve mainly result in a reduction of the red-green sense.

L'examen de la discrimination chromatique dans l'amblyopie strabique donne des resultats souvent anormaux, quand l'acuite visuelle est reduite a moins de 0,2. Les troubles se rapprochent de la deficience de la vision des couleurs qui est observee en vision laterale chez le sujet normal et plaident en faveur de la theorie d'apres laquelle les troubles fonctionnels de l'amblyopie strabique sont dus a des inhibitions au niveau du cortex visuel.

Verriest G. Des bases physiologiques de la parole rythmée (suite). In: Revue néo-scolastique. 1ᵉ année, n°2, 1894. pp. 112-139.