Macular pigment: influences on visual acuity and visibility

Macular carotenoid supplementation in subjects with atypical spatial profiles of macular pigment

“…MP is a blue light filter (Snodderly et al, 1984b) and a powerful antioxidant, (Khachik et al, 1997) and is therefore believed to protect against age-related macular degeneration (AMD), which is now the most common cause of blind registration in the western world (Klaver et al, 1998). In addition, MP's putative ability to enhance visual performance and comfort is also of interest (Bartlett and Eperjesi, 2008;Engles et al, 2007;Hammond and Wooten, 2005;Kvansakul et al, 2006;Loughman et al, 2010;Nolan et al, 2011;Rodriguez-Carmona et al, 2006;Hammond, 2007, 2008;Stringham et al, 2004;Wooten and Hammond, 2002).…”

Overview of Glare Types and Their Relationship With Macular Pigment Optical Density.

“…Perceptual difficulties occur when the visual system must adapt briskly to these sudden changes. Glare is caused by light entering the eye that does not aid vision and is most commonly luminance that is too intense or variable across the visual field 4 . Photostress or scotomatic glare occurs when a light source quickly decreases visual sensitivity.…”

“…Strictly speaking, MP does not provide direct optical absorption of the glare source but instead filters the masking luminance of the target proportional to the MPOD. A 2002 review article summarizes the mathematical derivation of the atmospheric haze coefficient by integrating the CIE photopic luminosity function and the spectral energy of the natural illuminant 4 . The authors proposed that the non-image forming portion of atmospheric light acts as a veiling luminance with respect to the targets seen through it.…”

“…This particle-dependent scatter largely dictates the quality of vision in an outdoor environment. Rayleigh (elastic / small particle) and Mie (inelastic / large particle) scattering are essential theories for describing the effects of light within the environment 4 . If scatter within the eye is wavelength dependent as it is in the clear atmosphere, then selectively screening the highly scattered short-wavelength light would improve the retinal image.…”

“…Types and Definitions:-Glare can be classified into several different types including 1) disability, 2) discomfort, 3) scotomatic (photostress), 4) dazzling and 5) dysphotopsia. This review will focus on the three areas of glare with the most existing literature: disability, discomfort and scotomatic.…”