AIM To evaluate the paradoxical pupillary constriction in darkness in patients with Pingelapese achromatopsia (PA), and to describe a connection between this phenomenon and the clinical features. METHODS 27 patients with PA were examined. All underwent a full ophthalmic examination which included Snellen visual acuity and ophthalmoscopy. Colour vision examination was performed with Ishihara p...

Assigning a basic color name to an object and rating the amount of a particular hue is a fundamental visual capability. Traditional color scaling studies have used increment flashes or isoluminant stimuli of a homogeneous color. Natural objects, however, do not contain a single color but are characterized by a distribution of different chromatic hues. Here we study color scaling using photograp...

The proanthocyanidin (PA) is the main flavonoids which affect the seed coat color in Brassica species. In this paper, characteristics of color development and accumulation of flavonoids were analyzed in the seeds of brown-seeded (B147) and yellow-seeded (B80) heading Chinese cabbage (Brassica rapa L. ssp. Pekinensis). It is found that the content of phenolic compounds in B147 were significantly...

PURPOSE To determine whether smokers have a reduced capacity for increased retinal blood flow velocity in darkness. METHODS The peak systolic flow velocities (V(S)) and end diastolic flow velocities (V(D)) were measured by ultrasound (i.e., color Doppler equipment), in light and darkness in the ophthalmic and central retinal arteries in 20 cigarette smokers and 20 matched nonsmokers. The resi...

In the early twentieth century, the Bauhaus revolutionized art and design by using simple colors and forms. Wassily Kandinsky was especially interested in the relationship of these two visual attributes and postulated a fundamental correspondence between color and form: yellow triangle, red square and blue circle. Subsequent empirical studies used preference judgments to test Kandinsky's origin...

BACKGROUND Color is commonly used for branding and coding consumer products including medications. People associate certain colors in tablets and capsules with the effect of the drug and the illness for which it is meant. Color coding was introduced in age-specific prepacked antimalarial drugs for preschool aged children in Nigeria by the National Malaria Control Committee. Yellow was designate...

A longstanding and unresolved question is how observers construct a discrete set of color categories to partition and label the continuous variations in light spectra, and how these categories might reflect the neural representation of color. We explored the properties of color naming and its relationship to color appearance by analyzing individual differences in color-naming and hue-scaling pa...

Pigments extracted from natural products are widely used for food coloration in Japan. An investigation concerning the photo-mutagenicity and photo-carcinogenicity of frequently used colorants in Japan was performed. Colorants examined were from Laccifer lacca (lac-color), Coccus cacti (cochineal-color), Carthamus tinctorius (carthamus yellow), Gardenia augusta (gardenia yellow and gardenia blu...

Sulfonephthaleins and benzeins differ only in the presence of a sulfonic acid group in the former. In aqueous medium, both exhibit two color changes, one from yellow to the strongly colored acid form in strongly acid medium, and one from yellow to the strongly colored basic form. The indicator constants of the sulfonephthaleins are about the same as those of the corresponding benzeins. In the p...

Aim: To evaluate the paradoxical pupillary constriction in darkness in patients with Pingelapese achromatopsia (PA), and to describe a connection between this phenomenon and the clinical features. Methods: 27 patients with PA were examined. All underwent a full ophthalmic examination which included Snellen visual acuity and ophthalmoscopy. Colour vision examination was performed with Ishihara p...