Corneal Health: Best Ways to Help Your Eyes

The cornea plays a crucial role in our vision. It is the transparent tissue at the front of the eyeball where light enters the eye. Approximately 65% to 75% of the refraction of light occurs in the cornea. The cornea also protects against external threats and harmful UV radiation. However, this vital part of our eye is constantly under siege. The cornea faces oxidative stress daily due to its high exposure to light and intense metabolic activity. The main culprit is ultraviolet radiation from the sun, which triggers the formation of Reactive Oxygen Species (ROS). These harmful free radicals can wreak havoc on the cells if not kept in check by antioxidants. While the cornea absorbs all UVC and most UVB rays, UVA rays are primarily absorbed by the lens.

All three spectrums of UV radiation have been shown to cause damage to different parts of the eyes,¹ and have been associated with a range of eye diseases, including cataract formation and corneal and retinal degeneration.²  In addition, oxidative stress threatens ocular tissues in conditions such as inflammation and diabetes, where a substantial amount of ROS can be produced.³

Oxidative stress has also been suggested to contribute to the hypoxia-reoxygenation injury of the cornea associated with prolonged wearing of hydrophilic contact lenses.⁴

The eyes need high amounts of antioxidants to nourish and protect the eyes against UV radiation and ROS damage.

Unlike other parts of the body, the cornea does not contain any blood vessels to nourish or protect the tissue against infection. The cornea instead receives its nourishment from the tears and aqueous humor, a fluid in the front of the eye that fills the chamber behind the cornea. The two antioxidants found in the tear film are vitamin C⁵   and Super Oxide Dismutase (SOD).⁶  

The cornea is composed chiefly of water, collagen, proteoglycans, and keratocytes. 

Good, balanced tear production, comprised of lipid, aqueous, and mucin components, is essential for keeping the cornea healthy. Balanced tears provide protection and maintain a moist and clean interface on the cornea.

The ocular surface system consists of various eye components structurally and functionally linked by continuous epithelia and common nervous, endocrine, vascular, immune, and endocrine systems. It includes the cornea, conjunctiva, lacrimal and meibomian glands, nasolacrimal duct, and eyelids.⁷

Dry eye disease is a multifactorial disease of the ocular surface where the quality of your tears is impaired. Dry eyes result from tear film instability, inflammation, hyperosmolarity, and epithelial damage.

Corneal Structure

Bowman’s layer contains collagen fibers that maintain the cornea’s shape.

Dua’s layer is the sixth layer in the cornea. It is located at the back of the cornea between the stroma and Descemet’s membrane. This layer is thought to play a vital role in the structure of the tissue that controls the flow of fluid from the eye. New research indicates that this makes an important contribution to the trabecular meshwork in the cornea’s periphery. A poorly functioning trabecular meshwork can lead to glaucoma.

Epithelium layer is filled with thousands of tiny nerve endings that make the cornea extremely sensitive to pain. Its function is to block foreign material while providing a nutrient-absorbing, oxygen-absorbing surface and signaling the brain to activate tear production.

Stroma layer consists of regularly arranged collagen fibers and sparsely distributed interconnected keratocytes, which are the cells for general repair and maintenance.

Diseases Related to the Cornea

Sjögren Syndrome

Sjögren Syndrome causes the immune system to attack glands and organs responsible for internal moisture and tear production. The main symptoms are dry eyes and dry mouth, but it can also affect other organs and parts of the body. Other symptoms include dry, itchy, burning eyes, dry mouth resulting in difficulty in swallowing and the feeling of cotton mouth, as well as joint pain, fatigue, frequent nosebleeds, skin, nose, vaginal dryness, and/or dry throat.

Sjögren’s syndrome can occur on its own or with other autoimmune conditions, like rheumatoid arthritis or lupus. The biggest population to get this disease are women in their 40’s and 50’s.

Keratoconus (KC)

Keratoconus (bulging of the cornea) is the most common type of corneal disorder. The cornea thins and protrudes, gradually takes on a conical rather than the normal rounded shape. This changes the refraction, resulting in blurred vision, glare/light sensitivity, poor night vision, and possibly multiple imaging.

Underlying causes can include oxidative damage due to free radicals, allergies, magnesium deficiency⁸, genetic disposition, and respiratory conditions. Other vision conditions associated with keratoconus include retinitis pigmentosa and Leber’s disease.

Other factors, such as chronic eye rubbing and wearing hard contact lenses, are associated with keratoconus.

Keratoconus prevalence is positively associated with vitamin D deficiency, mitigating collagen degradation, inflammation, oxidative stress, and copper metabolism.⁹

Fuch’s Corneal Dystrophy

Fuchs’ Dystrophy is a genetic eye disease that primarily causes corneal swelling (edema) and is most common in individuals aged 30 to 40. It affects women 2-4 times more frequently and severely than men. This slowly progressing condition typically impacts both eyes, leading to the deterioration of the inner cell layer of the cornea. As the inner layers thicken, blisters form in other layers, and when these blisters burst, they can cause significant pain. The disease results in the gradual death of endothelial cells, leading to fluid buildup in the cornea, which causes thickening and blurred vision.

Essential Nutrients for Corneal and Tear Health

Nutrients that support healthy tear and corneal function include: omega-3 fatty acids; vitamins A, B12, C, and D; selenium; curcumin; and flavonoids.

Vitamin A helps in the production of mucus, which keeps the cornea moist and free from infections, and is vital for maintaining the health of the corneal surface.

Good food sources include fatty fish, eggs, dairy, dark, leafy greens, broccoli, fruit, organ and yellow vegetables, and organ meats.

Vitamin C is an antioxidant that helps protect the cornea from oxidative stress and supports collagen synthesis. It is essential for corneal structure and repair and is one of the precursors for glutathione production. A diet rich in vitamin C can help reduce the risk of cataracts and other age-related eye diseases while promoting healing.¹⁰   Vitamin C plays an important role as a potent antioxidant that protects the eye from light-induced stress and tissue damage.¹¹

Deficiencies are commonly seen with restricted diets such as ketogenic, alcoholism, gastric bypass issues, and those with increased risk of infection.

Good food sources include Citrus fruits, black currents, strawberries, sweet red pepper, Brussels sprouts, potatoes, and broccoli.

Vitamin D benefits include the control of metabolism, bone formation, and immunity.¹²

Good food sources include egg yolks, salmon, mushrooms, citric fruits, sardines, milk, and liver.

Glutathione (GSH) can regenerate other important antioxidants, Vitamins C and E, back to their active forms. GSH accumulates mainly in the epithelium layer of the cornea, where GSH concentration is five-fold higher than that in the stroma.¹³   GSH plays a pivotal role in maintaining the normal hydration levels in the cornea,¹⁴  protecting the integrity of the cellular membrane, and degrading xenobiotics (substances foreign to the body or to an ecological system).

Lutein and Zeaxanthin are essential carotenoids that protect the retina and lens from age-related changes,¹⁵   acting as potent antioxidants in the eyes and helping to protect against the negative impact of UV radiation exposure. Lutein, zeaxanthin, and mesozeaxanthin are absorbers of blue visible light and crucial in the modern world of digital screens.

Good food sources include carrots, eggs, sweet corn, spinach, kale, broccoli, pumpkin, romaine lettuce, Brussels sprouts, winter squash, parsley, sweet potatoes, and bell peppers.

Omega-3 Fatty Acids. A pilot study on Omega-3 supplementation found they are neuroprotective to corneal nerves in dry eye disease.¹⁶  Another study showed that omega-3 supplementation was helpful for managing dry eye disease.¹⁷

Super Oxide Dismutase (SOD) is found in the tear film along with ascorbic acid. SOD is essential in providing corneal protection, helping to prevent spontaneous age-related loss of endothelial cells and increased susceptibility to oxidative stress and inflammatory damage.

Good food sources include cruciferous vegetables (broccoli, cabbage, Brussels sprouts), cantaloupe and honeydew melon, wheatgrass, and barley grass.

Zinc is crucial for the metabolism of vitamin A and maintaining a healthy retina and cornea. This mineral is mainly concentrated in the corneal epithelium and posterior stroma.¹⁸  Zinc deficiency can lead to impaired vision and increased impaired wound healing.

Good food sources are shitake mushrooms, green peas, spinach, beet greens, asparagus, okra, sweet corn, broccoli, meat, shellfish, oysters, legumes, seeds and nuts.

Lifestyle Considerations

Keep hydrated. Proper hydration is crucial for maintaining the moisture balance in the cornea. As discussed above, the cornea is made up of several layers, the largest being the stroma, which occupies approximately 90% of the total corneal thickness.¹⁹  Drinking adequate fluids ensures proper integrity of the cornea.

Eat a balanced diet consisting of fruits and vegetables, beans, bell peppers, nuts and eggs, foods high in vitamins A, C, and E, and omega-3 fatty acids, zinc, and lutein. For protein and essential fatty acids, include fatty fish like salmon, tuna, mackerel, anchovies, and trout. For vegetarians, tempeh has twice the amount of protein per serving than meat.

Exercise regularly – at a bare minimum, do an endurance activity and light weight exercises for at least 20 minutes per day, 4-5 times per week.

Keep blinking – Computer users have been shown in studies to blink less, affecting dry eyes symptoms over time.

Take regular breaks from computers and near work to massage acupressure points around the eyes and do eye exercises. For our free eye exercise e-booklet, go to https://www.naturaleyecare.com/blog/free-eye-exercise-ebook/

Suggested Supplements

Advanced Eye & Vision Support Formula (whole food) 60 vcaps

Oclumed Eye Drops 10ml Bottle (2% NAC solution)

OPTASE® Dry Eye INTENSE Drops (.33 fl oz)

Eyebright (Eyebrite) Drops (with MSM) 1oz

Dr. Grossman’s Advanced Eye and Dr. G’s Whole Food Superfood Multi1 20 Vcap Combo – 2 months supply

ReVision Formula (wild-crafted herbal formula) 2 oz – based on classic Chinese medicine Liver tonic formula to help support healthy circulation and blood flow throughout the eyes and body.

Retinal Support (wild-crafted herbal formula) 2 oz

Packages

Corneal Support Package 1

Corneal Support Package 2

Dry Eye Package 2

Dry Eye Package 3

Dry Eye Package 4

Recommended Books

Natural Eye Care: Your Guide to Healthy Vision and Healing

Natural Brain Support: Your Guide to Preventing and Treating Alzheimer’s, Dementia, and Other Related Diseases Naturally

Natural Parkinson’s Support (ebook): Your Guide to Preventing and Managing Parkinson’s