The food that we consume has an extensive effect on our health, for better or worse. A poor diet can affect weight, heart health, and cause conditions such as Type 2 diabetes, cancer, immune disorders, among others. A healthy, well-balanced diet full of minerals and nutrients can go a long way in preventing disease and extending life. Eye health, and excuse me for the pun, is often overlooked. Healthy eyes can be supported by a healthy diet and lifestyle.
While many diets advise us to limit fat intake, fat is necessary for the body to function. Regarding eye health, omega-3 fatty acids are powerfully beneficial to eye health. Omega-3s are a type of essential fatty acid (EFA). They are not produced in the body, and because of this, we need to consume them to reap their benefit. A lack of omega-3 fatty acids in an adult diet can cause both dry eye and meibomian gland dysfunction (the meibomian gland secretes oil into tears, however, when it does not function correctly, tears evaporate quickly, leading to dry eye sensation). A lack of omega-3s in diets can also contribute to macular degeneration.
Macular degeneration (also known as age-related macular degeneration or AMD) is a serious eye condition that can lead to a wet, bleeding form of the disease that can cause significant central vision loss leading to a blind spot and greatly reduced visual acuity. Macular degeneration occurs when the macula, a small portion of the central retina and responsible for our central vision and color perception, deteriorates, sometimes slowly and sometimes much more rapidly. At end-stage disease, a large portion of the central area of vision is lost, leading to poor visual detail and a severely diminished ability to read and write. Macular degeneration tends to affect people who are over the age of 60. There are measures that individuals can do to help prevent macular degeneration.
In a 2009 study, it was found that those who consumed a higher-degree of omega-3 fatty acids were 30% less likely to develop macular degeneration over a 12-year period. Just increasing your consumption of oily fish to once a week can help protect your eyes. Some natural sources of omega-3 rich foods include flax seeds, walnuts, and dark, leafy green vegetables. There are also many over-the-counter omega-3 supplements.
When looking for a supplement you will want to find one that does not have polychlorinated biphenyls, which are a pollutant that was banned back in 1979 but is still found in oceans. It is also best to get a supplement that was made in Norway, as they have the highest standards for creating fish oil products in the world. You also want to choose a wild caught fish source, rather than farmed as farmed fish can have too high a level of omega 6 which can cause inflammation, and choosing a fish oil derived from anchovies, mackerel, and sardines. These sources are the most eco-friendly. Lastly, ensure that the fish oil has gone through a process called triple molecular distillation. This will refine the oil and remove potential contaminants.
Lutein and zeaxanthin are two other nutrients that protect against macular degeneration. These nutrients are called carotenoids. Luetin is found inside the macular cells of the eye. Research published in Archives of Biochemistry and Biophysics found that lutein and zeaxanthin both help prevent macular degeneration by filtering short-wavelength light, which reduced the generation of free radicals in the eye. Free radicals damage cell walls and lead to loss of cell defense and structure. Increased amounts of Lutein in the body can also aid macular health, as those who possess higher degrees of macular pigment (e.g. Lutein) are less likely to develop macular degeneration.
It is believed that lutein, zeaxanthin and meso-zeaxanthin, all pigments found in the retina’s macula, block blue light from reaching underlying retinal structures, thereby reducing the risk of light-induced oxidative (i.e. free radical creation) damage that leads to macular degeneration.
Sometimes it is not what we eat that affects our vision, but it is a lack of something entering our body through a different means. Contact lenses, when not made of high oxygen transmissible material and/or when worn overnight, impede oxygen flow to the eye which results in a condition called hypoxia. Hypoxia causes the cornea to swell (edema), and can result in blurred vision, when left untreated it can also leave you susceptible to red eye (inflammation) and infections that can lead to permanent vision loss in the later case. Signs and symptoms of corneal hypoxia include:
● Blurred vision
● blood vessels growing into the cornea (neovascularization)
● red or bloodshot eyes
● ocular pain/ache
● light sensitivity (photophobia)
Rigid gas permeable and soft lenses made from silicon-hydrogel material are best at least impeding the flow of oxygen to the cornea.