The study involved 4187 subjects age 65 years in Europe whose vision was assessed and a blood sample taken. Lifetime exposure to unfiltered solar radiation (UV-B sun tanning rays) reduced the odds of developing shortsightedness (seeing near but not far). Exposure to sunlight between age 14-29 years, as determined by a survey, was associated with a reduced odds of becoming myopic. A surprise finding was subjects with the highest blood level of lutein were 40% less likely to become myopic. [JAMA Ophthalmology Dec 2016; Science Daily Dec 1, 2016]
A study published four years ago revealed that less severe myopic individuals taking a lutein dietary supplement (10 milligrams/day) for up to 3 months developed thicker macular pigment (lutein/zeaxanthin) whereas individuals with more severe myopia (-4 dioptics and up) did not experience a thickening of their macular pigment. [Japanese journal Ophthalmology Sept 2012]
Another study shows individuals with thicker dietary pigment (lutein) at the back of their eyes also tended to have shorter (front to back measurement). Myopic individuals may have longer eyes and therefore objects are focused in front of the retina which is the definition of myopia. [Graefes Archives Clinical Experimental Ophthalmology June 2013]
Lutein’s ability to alter the length of the eyes is captured in an experiment where it was shown that beta carotene, lutein and zeaxanthin activate the production of hyaluronic acid in skin cells. [Bioscience Biotechnology Biochemistry 2013] If these dietary derived carotenoid pigments (beta carotene, lutein/zeaxanthin) activate hyaluronic acid sythesis in the eyes, this might explain why lutein has a regressive effect upon myopia as hyaluronic acid is the space-filling molecule in the vitreous jelly of the eyes.
Another intriguing animal study reveals the positioning of a negative power lens in front of an animal’s eyes causes a compensatory shift in the length of the eye so the eye is myopic (nearsighted) when the lens is removed days later. During the period when the eye was becoming longer, which shifts the focus point in front of the retina, the composition of the wall of the eye is changed. There is less hyaluronic acid, a jelly-like water-holding, space-filling molecule during the period when a defocusing lens is employed. [Investigative Ophthalmology Visual Science July 2007]
Another experiment has shown that the exposure of the vitreous jelly that fills the eyes to light in the visible spectrum when a light-sensitizing vitamin B2 (riboflavin) is present results in a breakdown of the vitreous gel, namely the hyaluronic acid in the vitreous. [Current Eye Research July 1994]
Another revealing study was conducted among myopic subjects who underwent laser surgery to alter the curvature of their cornea to reduce dependence upon eyeglasses. Four of seventeen laser-treated subjects experience a return to their myopic state following laser surgery, all having used topical steroid eye drops that suppresses formation of hyaluronic acid. [Acta Ophthalmologica April 1994]
Lutein and hyaluronic acid supplements may be appropriate for young adults who experience an onset of myopia (nearsightedness), particularly those individuals with severely progressive myopia.