Doctor's Note

I covered two other leading causes of blindness—age-related macular degeneration, and diabetic retinopathy—in Preventing Macular Degeneration with Diet. I’ll close this three-part series on preventing vision loss by addressing the world’s leading cause of blindness, cataracts, in Preventing Cataracts with Diet. For more on lutein and zeaxanthin, and where to get them in the diet, see my video Egg Industry Blind Spot

For additional context, check out my associated blog posts:  Preserving Vision Through DietEating Green to Prevent CancerThe Anti-Wrinkle Diet; and Prevent Breast Cancer by Any Greens Necessary.

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  • Michael Greger M.D.

    I covered two other leading causes of blindness, age-related macular degeneration and diabetic retinopathy, in yesterday’s video. Tomorrow I’ll close this three-part series on preventing vision loss by addressing the world’s leading cause of blindness, cataracts. For more on lutein and zeaxanthin and where to get them in the diet, see my video Egg Industry Blind Spot. And there are also hundreds of other videos on more than a thousand subjects—please feel free to explore them.

    • HemoDynamic

      I hear a song coming on: “I can see clearly now the pigments on.  I can see all Mountain’s far and away. . .”
      Great Segment!

      • HemoDynamic, M.D.

        I can see for Miles and Miles; I can see for Miles and Miles, . . .

  • Great video!  This is the first time I have seen Lutein and Zeaxanthin associated with Glaucoma risk reduction.  Traditionally they have been recommended for the reduction of Macular Degeneration (ARMD) risk.  New data does suggest that the earliest measurable changes in glaucoma may be the loss of retinal ganglion cells in the macula, so supplementation with Lutein/Zeaxanthin may help reduce that risk.  

    How much lutein and zeaxanthin though?  The best available data for ARMD risk is that 10-20 mg of lutein per day and 2-4mg of zeaxanthin is a good amount.  There is no current data on glaucoma, but that same range would be reasonable.

    Foods that are richest in lutein include kale, spinach, collards and turnip greens.  Eggs by contrast have a mere 0.15 mg of lutein each.With respect to glaucoma, the tricky part is that the early changes occur so slowly and insidiously that there are NO symptoms for most people.  Also, there is no evidence that glaucoma related vision loss can be restored with medical or nutritional intervention. Therefore, it is important to have a thorough eye exam periodically.  The frequency would depend upon your age and risk (family history, ethnicity, etc).  A good rule of thumb is an exam every couple of years until you are 50, then every year.New technology called OCT allows us to measure the optic nerve and macula with incredible precision (down to about 6/1000 of a millimeter).  This can catch glaucoma more than a decade before vision problems would be noticed by the patient.  Then appropriate interventions can be prescribed. If you have concerns or at high risk, seek out a doctor who has this technology and get a baseline measurement that can be tracked over time as needed.  You can read more about OCT here:

    • Thea

      Dr. John Henahan:  I am a lay person and appreciate your taking the time to write your post.  I know someone with terrible eye problems and the more we know, the better.

      I am curious about one aspect of your post, especially since get my eyes checked about once a decade.  You wrote: “there is no evidence that glaucoma related vision loss can be restored with medical or nutritional intervention.”  and then you wrote: “Then appropriate interventions can be prescribed.”

      I’m not trying to be snotty.  I honestly want to know: If we have no known medical or nutritional intervention, what “appropriate interventions” are there? 

      I have found in dealing with my dog’s health issues that while we can often find a diagnosis (at least we think we know what it is), there is more often when there is nothing that can really be done about it.  So, I now look ahead for every test and first ask: if this comes back positive, is there really anything we can do about it?

      I think that a similar approach for humans makes sense.  So, is there really anything that can be done if early glaucoma is detected?

      Thanks for any insights you have.

      • Great question!  There are VERY EFFECTIVE interventions that can prevent further loss of vision, but there is no real way that we know of to reverse the damage that has already been done. Most commonly the treatment is one eye drop in the effected eye(s) at bedtime. 

        Also, it should be noted that most patients aren’t even aware of the loss of peripheral vision that accompanies glaucoma, and by the time they are aware vision loss likely exceeds 90% of vision. Since the optic nerve becomes more fragile as it becomes more damaged, it is much harder to preserve remaining vision in someone with advanced glaucoma vs early glaucoma.  Hence early detection is critical.

        Hope this helps!

        • Thea

          Dr. John Henahan:  Thank you for the clarification.  That helps a lot.  I hadn’t caught the distinction in your original post, but now I see it is there.  Thanks for the reply. You make an excellent argument for getting those checkups you talked about.

          FYI: My relative currently has high pressure in one eye, enough to raise concerns of blindness in that eye.  I don’t know the technical term for this problem, but I know that the eye drops she has been given (and she’s tried quite a few varieties) have caused severe life-altering bad side reactions.  I hope the glaucoma drops are more user-friendly.

          Thanks again for your response. Clearly, the best thing to do is follow the information in this video, eat healthy, and hopefully avoid glaucoma in the first place!

          • Seri

             thanks for asking Thea, I was wondering the same thing. :-)

    • Valnaples

      Dr. Henahan…any prevention advice at all for retina issues, i.e., retinal tears…detachments, etc? I have a high school friend who has had a number of laser treatments for retinals tears…I am wondering if nutrition helps with this at all? thank you!

  • April Barnswell

    This is such welcome news! Both my brother and I are at risk of glaucoma – borderline cases. I eat kale and collards weekly, as well as carrots daily, so this is very good news indeed! Dr. Greger, just earlier ths week I was searching your video archives, hoping to find a link behind nutrition and preventing glaucoma, and today you posted some vital information! Thank you so much. This website is such a wonderful public resource. I check it daily for your updates.

  • Veguyan

    Do we need to cook our tomatoes for the benefit of Lycopene, or will juicing the tomatoes give us the same benefit?

    • NickyC

      Hi Veguyan. Great question. While I personally advocate the consumption of primarily raw fruits and veggies, there are some instances where cooking a fruit or vegetable has beneficial side effects. Cooking tomatoes and the increase in lycopene bioavailability is one such instance. Dr. Gregor discusses this very topic in this video linked here: . As you will see, cooking tomatoes does in fact increase the bioavailability of lycopene. I would deduce that while there are benefits to drinking raw tomato juice, if lycopene consumption is what you are looking for, cooking the tomato will have a greater impact. This other video also discusses the benefits associated with cooking tomatoes vs. consuming them raw:

  • I eat kale every day, and peaches when seasonal and also lots of spinach and tomatoes (cooked and raw).  The eye-doctor still wants me in there every 6 months because I have early warning signs of glaucoma :(

  • Donna

    Canned or dried peaches? Why not fresh peaches?

    • Michael Greger M.D.

       If you can find them then go fresh!

  • Tricia

    Does the collard greens, kale and spinach have to be fresh. Can it be frozen or canned?

  • Susan

    This is terrific information. Now, to get my meat and potatoes eating husband who is worried about age-related macular degeneration to eat healthier vegetables than just baby greens, carrots and tomatoes. When I served him kale, as well as spinach, he ate a tiny bit of spinach and left the kale for me.

    His father had glaucoma as well as age-related macular degeneration, and he keeps speaking with his ophthalmologist about it and has drops to put into his eyes, but he does not like vegetables.

    What suggestions do you have to empower him to eat more nutritious veggies?

  • Lisamarie

    What if you already have glaucoma? Is there any certain nutrient we can/should take to slow down vision loss in addition to, of course, prescribed eye drops?

  • James

    I drink loads of Coffee and have glaucoma, with no family history. Maybe the cause.

  • lori

    Hi Dr Greger. Eye illnesses are of great interest to me. In the summer of ’99, my mom suddenly lost her sight, and when taken to the dr, then hospital, to acquire massive doses of intravenous prednesone and a temporal biopsy later, it was found she had temporal arteritis (inflammation of the blood vessels in or behind the eyes which leads to blindness). Dr’s had not figured out why for months previous to her overnight blindness what was causing (what I found to be precursor) pain in her chest/torso/and arms.

    When we were given the TA diagnosis, I researched it and found those previous pains (that also seemed to come on pretty quickly the year before) were polymyalsia rheumatica. (sp) Also after the blindness, we learned of a blood test called the “sed rate test” where they took her blood and looked at how fast or slow the sedementation rate was in it. (this is very rudimentary version on my part). I believe it was the prednesone that brought down her ‘sed rate’ to normal. I would so much like for you to add this to your series of eye illnesses (causes for blindness) as it seems temporal arteritis is not so common and so not well known. If it had been, perhaps the doctors could have diagnosed my mom’s torso pains (and not just think it was heart issues like they did) prior to the TA and her sight probably would have been saved, in my opinion. It also seems to boil down to just plain inflammation–caused by a poor diet. But then, my dad did live to be 87 and my mom is currently 95. Go figure.

    One other note, just a week or so before my mom went blind, my parents saw their doctor because my mom’s appetite was diminished and she just seemed down. He gave them a sample pack of an anti-depressant whose name escapes me at this moment. My dad started to give my mom the anti-depressant and a week later she went blind. In reading the fine print of this medication, my sister discovered that it could cause arteritis. Don’t know if that was the leading cause, or if it hastened the end result that was already well on its way. It’s all pretty interesting to say the least. Would love to see this illness featured by you. :-)

    Thank you for your consideration for all that you do.

  • connie

    I have a terrible eye allergy, swollen, redness, itching, i overreact to everything, I used cortisone drops , very often, which diet would be good for me thanks

  • lovestobevegan

    This dish replaces the traditional Corned Beef and Cabbage.

    Corn, Beets, and Collards

    – 1 package frozen corn / 1 ½ cups fresh corn
    – 3 medium beets, cubed
    – 1 bunch organic* collards, cut into ribbons
    – 2 red onions, thinly sliced
    – 1 yellow onion, thinly sliced
    – ½ tsp white pepper
    – ½ tsp black pepper
    – 1 tbsp apple cider vinegar
    – 1 lemon

    Cook onion on high heat in a large skillet with a splash of water for 1-2 minutes covered. Lower heat and cook, covered, until onions begin to brown, about 15 minutes. Add beets, pepper, and apple cider vinegar.
    Cook on medium heat, covered, until beets tender, about 20 minutes. Add corn, collards, and juice of lemon. Cook a couple minutes longer until collards turn bright green.

    *Collards may contain pesticides of special concern so choose organic.

    Bookmark my new Plant-Based Emporium Facebook page for all my latest recipes.

    ~Complements of lovestobevegan

    • almost there

      Consider using organic beets. The vast majority of sugar beets I have read are GMO

  • Aurora1

    Great video. Can the leafy greens be cooked or raw, or will cooking diminish the bioavailability of the lutein and zeaxanthin?

    • Joseph Gonzales R.D.

      Both raw and cooked greens will supply the carotenoids and a bit of added fat will boost availability. For more information on this check out Brenda Davis’s book Becoming Raw. She did a guest post about paleo diets, too.