Spectral and directional reflectance of the fovea in diabetes mellitus: Photoreceptor integrity, macular pigment and lens

Our aim was to assess the integrity of the photoreceptors in the fovea, and to measure the optical density of the macular pigment and the eye lens in patients with diabetes mellitus, and to compare the results with those of a group of healthy subjects. The directional and spectral properties of the light reflected from a 1.9 deg field centered...

Absorption of the eye lens and macular pigment derived from the reflectance of cone photoreceptors

We measured the amplitude of the directional component of the bleached fundus reflectance, the so-called optical Stiles-Crawford effect, as a function of wavelength. The directional reflectance originates from within the outer segments of the photoreceptors. Thus only two anterior absorbers are of importance: Macular pigment and the crystalline...

On the cause of disability glare and its dependence on glare angle, age and ocular pigmentation

Background: In the 1920s and 1930s, disability glare was a topic of great interest in the Commission Internationale de l'Éclairage (CIE). The Second World War prevented agreement being reached on a standard to quantify disability glare but the Stiles-Holladay formula was widely accepted as such. In 1983, CIE started a new effort to develop a CIE...

Lens aging in relation to nutritional determinants and possible risk factors for age-related cataract

Objective: To investigate whether nutritional factors and possible risk factors for cataract influence the lens optical density (LOD). Design: Three hundred seventy-six subjects, aged 18 to 75 years, were recruited. In a cross-sectional design, serum was analyzed for lutein, zeaxanthin, vitamin C, α-tocopherol, and cholesterol levels. Adipose...

Macular pigment density in relation to serum and adipose tissue concentrations of lutein and serum concentrations of zeaxanthin

Background: Macular pigment (MP), concentrated in the central area of the retina, contains the carotenoids lutein and zeaxanthin. A low MP density could be a risk factor for age-related macular degeneration. Little information is available regarding MP density in relation to serum lutein and zeaxanthin and adipose lutein concentrations in a...

Recovery from the increase of the Stiles-Crawford effect after bleaching

THE Stiles–Crawford effect1,2, or the dependence of luminous efficiency on the eccentricity of the point of entry of the light in the pupil, is a function of the wavelength of the light. In Fig. 1 is given the inverse 1/ of the luminous efficiency as a function of wave-length at a distance of 3.5 mm from the point of maximum efficiency,...