Free eye-health education from a nonprofit
All Heal Organization provides whole-person eye-health learning for anyone who wants to understand what researchers know about vision, lifestyle and the body.
This page is a free educational resource.
Nothing here is medical advice, and nothing here replaces the care of your licensed eye doctor.
If you have sudden vision changes, eye pain or an eye injury, seek care now. See the urgent signs
Why eye health is a whole-body conversation
The eyes do not live in isolation from the rest of the body.
Many eye tissues rely on a carefully regulated blood supply.
The cornea and lens have no blood vessels. They receive nutrients through the surrounding fluids.
The retina is one of the most metabolically active tissues in the human body, so it is sensitive to changes in nutrition, blood sugar and oxygen supply.
Researchers have long studied the relationship between chronic blood-sugar elevation and damage to the small blood vessels that feed the retina and optic nerve.
Sleep is another area scientists continue to examine, because the pressure inside the eye naturally fluctuates during the night.
Prolonged screen use is something many people ask about. Researchers have noted that reduced blinking during screen time is associated with tear-film instability and eye-surface discomfort.
Researchers are studying whether stress affects blood flow to the optic nerve.
Lighting affects visual comfort and sleep timing.
A whole-person view of eye health means asking what the rest of the body is doing, and bringing that question to the conversation with your eye doctor.
Glaucoma: what researchers know
Glaucoma is a group of eye conditions in which damage to the optic nerve can lead to vision loss, especially when it is not found and treated.
Vision lost to glaucoma cannot be restored.
Prescribed treatment, such as eye drops, laser or surgery, can slow or prevent further loss.
Eye care professionals typically screen for glaucoma by measuring intraocular pressure (the fluid pressure inside the eye), examining the optic nerve head, and testing side vision with a visual field test.
Some people develop optic nerve damage with pressure readings in the normal range, a form called normal-tension glaucoma. Others carry elevated pressure for years without nerve damage.
This is why regular comprehensive eye exams matter more than any single measurement.
Factors people commonly ask about
Researchers have studied whether regular aerobic exercise is associated with lower intraocular pressure. Some studies suggest a modest relationship worth discussing with a doctor.
Several nutrients have been studied in glaucoma research. No supplement has been shown to treat glaucoma.
Some researchers have explored how sleeping position and caffeine intake may influence pressure readings.
Blood flow to the optic nerve is another area of ongoing research. Scientists are looking at circulation, blood pressure variability and nerve health.
Questions to bring to your eye doctor
How often should I have a comprehensive exam, given my personal risk factors?
Does my eye pressure vary, and at what time of day is it usually measured?
Are there habits, such as diet, exercise or sleep position, that you think are worth adjusting in my situation?
What does my optic nerve look like now, and how will we track any change over time?
Cataracts: what researchers know
A cataract is a clouding of the eye's natural lens, the clear structure behind the pupil that focuses light onto the retina.
Most cataracts develop gradually as proteins within the lens change over decades. They are most common in people over 60, though they can occur at any age.
Eye doctors detect cataracts during a dilated eye exam, where they can view the lens directly and assess how it affects vision.
The standard medical approach to a cataract that significantly impairs daily life is surgical removal of the clouded lens and replacement with an artificial one. The procedure has a well-established safety record.
Factors people commonly ask about
Ultraviolet light is one of the most studied environmental factors associated with cataract development. Researchers have examined whether UV-protective eyewear worn outdoors may be relevant to long-term lens health.
Antioxidant nutrients such as lutein, zeaxanthin and vitamins C and E have been studied in relation to cataracts. Large trials have not shown a clear benefit.
Researchers have noted associations between blood-sugar dysregulation and earlier cataract development.
Research has consistently found associations between smoking and accelerated lens changes.
Questions to bring to your eye doctor
If you find a cataract, when would a surgical evaluation make sense?
Are there UV-protective measures or nutritional habits you believe are worth considering in my situation?
How is my lens health tracked at each visit, and what signs would show a meaningful change?
Macular degeneration: what researchers know
Age-related macular degeneration (AMD) is a condition in which the macula, the small central area of the retina responsible for sharp detailed vision, gradually changes. That can affect reading, recognizing faces and other fine-detail tasks.
AMD is described as dry or wet.
Dry AMD accounts for most cases. Its course varies, and it can turn into wet AMD.
Wet AMD involves abnormal blood vessels that can leak and cause rapid changes in central vision.
Injections given by a retina specialist are the standard treatment for wet AMD.
Straight lines that look wavy, or a new blurred or missing spot in central vision, are reasons to contact an eye doctor promptly.
Eye doctors detect AMD during a dilated exam. They may use imaging such as optical coherence tomography (OCT) to view the layers of the retina and track changes over time.
Factors people commonly ask about
The AREDS and AREDS2 clinical trials, funded by the National Eye Institute, tested a specific antioxidant and mineral formulation.
It slowed progression to advanced AMD in people with intermediate AMD, or with advanced AMD in one eye. It showed no benefit for people with early AMD or none.
AREDS2 found that adding omega-3 fatty acids gave no further benefit.
The original AREDS formula contained beta-carotene, which raised lung-cancer risk in smokers. AREDS2 replaced it with lutein and zeaxanthin.
Lutein and zeaxanthin are carotenoids found in high concentrations in the macula itself. They are also found in foods such as kale, spinach and eggs, and they are among the most studied nutrients in AMD research.
Research consistently identifies smoking as a factor associated with higher AMD risk and faster progression.
Many people ask about blue light from screens. Current evidence does not show that ordinary screen use causes AMD or retinal damage.
Vascular health appears in AMD research as an area of interest, reflecting the retina's dependence on a healthy blood supply.
Questions to bring to your eye doctor
What stage of AMD, if any, do you see in my eyes, and how are we monitoring it?
Should I discuss the AREDS2 formulation with you, given my situation?
What dietary or lifestyle factors do you think are most worth my attention?
Based on my exam and risk factors, when should I return?
Dry eye: what researchers know
Dry eye disease is a condition in which the tear film, the thin protective layer covering the eye's surface, is too scant or unstable. It can bring discomfort, fluctuating vision, and sensitivity to light or wind.
Eye doctors assess dry eye with tear production tests, checks of tear-film stability, and examination of the eyelid margins and meibomian glands. Those glands produce the oily layer that slows tear evaporation.
Factors people commonly ask about
Screen use comes up in most dry eye conversations. Researchers have documented that blinking decreases during focused screen tasks, so the tear film is refreshed less often.
Low humidity, air conditioning, heating and wind are frequently discussed, because all of them speed tear evaporation.
Omega-3 fatty acids have been studied for dry eye, with mixed results. A large 2018 trial funded by the National Eye Institute found no benefit over placebo.
Hormonal changes, particularly around menopause, are frequently studied in dry eye research.
Certain medications are known to affect tear production, including antihistamines, antidepressants and some blood pressure medications. Reviewing a full medication list with an eye doctor can be informative.
Do not stop a prescribed medication without asking the prescriber.
Questions to bring to your eye doctor
If dry eye is present, is it a production problem, an evaporation problem, or both?
Are my meibomian glands working well, and what does the exam show?
Could any of my current medications affect my tears?
What environmental or behavioral changes would you suggest for my situation?
When to see an eye doctor without delay
Some eye symptoms need prompt evaluation and should not be watched at home or managed with lifestyle changes alone.
Do not wait for a routine appointment or an office callback for any of the following. If emergency eye care is not available, go to an emergency department.
Sudden loss of vision in one or both eyes, even briefly, is an emergency. Seek care immediately.
A sudden increase in floaters, especially with flashes of light, can signal a retinal tear or detachment.
A shadow, curtain or dark area spreading across part of your vision is an urgent sign.
Eye pain with redness, particularly with nausea, headache or halos around lights, may signal a sudden rise in eye pressure that needs emergency care.
New, sudden double vision needs urgent assessment, even if you feel tired.
If vision changes come with weakness, facial drooping, trouble speaking or a severe headache, call 911.
Any blow or injury to the eye, or any object in the eye, should be assessed by an eye care professional or emergency room as soon as possible.
If a chemical gets in the eye, flush it at once with plenty of clean running water for at least 15 to 20 minutes. Call Poison Control at 1-800-222-1222 or seek emergency care while you flush.
This list is not complete. For other new eye symptoms, contact an eye doctor promptly.
If you do not have an eye care provider, community health centers and programs such as EyeCare America, a program of the Foundation of the American Academy of Ophthalmology for people 65 and older, may be able to help.
Why All Heal exists
My name is Dr. Glen Swartwout.
I am a naturopathic optometrist, now retired from licensed practice.
A health challenge in my twenties led me to ask how the whole body relates to the eyes.
That question became my life's work in education.
It is the foundation of what All Heal Organization offers.
What All Heal Organization offers
All Heal Organization is a Hawaii 501(c)(3) nonprofit.
Its education is free.
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Educational information only. This page is provided for general education by All Heal Organization, a Hawaii 501(c)(3) nonprofit.
Nothing on this page diagnoses, treats, cures or prevents any disease or health condition.
Nothing here replaces the judgment or care of your licensed eye doctor or any other qualified health care provider.
If you have concerns about your vision, please consult a licensed eye care professional.