From my experience, I think adopting a ketogenic lifestyle will cause temporary blurred vision in some people. I noticed that after I went on an LCHF ketogenic way of eating my vision started to get blurry. I wear reading glasses and at times they didn’t seem strong enough. There were times I would put them on to read captions on the television. I had never done that before.
Since my glasses are only for reading, I never needed them to view numbers on digital clocks in the house. However, I noticed I was having difficulty reading numbers and had to put on my reading glasses to clear things up. That was a new and very unwelcome development. And my goodness, trying to read the small print on nutrition labels when food shopping was almost impossible. I started doubling up on my glasses for in order to read fine print. Yes, I looked dorky, but I had to put on 2 pairs of glasses to read such things (a woman had to do what a woman had to do).
As annoying as it was I didn’t panic. It made me think of the bouts of blurry vision I would have from time to time prior to keto eating. Some days my vision would be blurry and other days as clear as a bell. I couldn’t understand why the large fluctuations in vision, but being the analytical type I decided to track what I ate, where I went and whatever else might be influencing the changes in my vision.
What I had noticed was I would fluctuate from eating very low carb on some days and not so on other days. Some days I’d eat one meal a day that consisted of a huge salad and other days I ate more frequently with more traditional foods. My traditional foods were still low in carb, but I guess with the additional meals it added up to enough carbs that would modify my vision accordingly. I couldn’t figure out how or why the carbs were affecting my vision, but drastic reductions in carbs seemed to be the cause of blurriness. Before you ask, no I’m not diabetic. BTW, being outdoors seems to be good for vision (at least in my case).
Enduring the Blurred Vision while LCHF
As I said earlier, I didn’t panic. Logically, I couldn’t see how cutting down on something that the body doesn’t really need much of could injure my body. It just made me realize that my body had become more addicted to carbs than I had originally thought. So, I continued eating LCHF and endured the blurry vision. Then, one day about a month into my ketogenic lifestyle, my vision seemed to clear up. It was like someone cleaned the computer screen and all the fuzzy edges were gone. I still need to use reading glasses, but now they seem to be the right strength. My vision has returned to what it was a little over a month ago before the month-long LCHF induced blurriness.
When my vision cleared I decided to test my urine ketones. I know it is not the most effective way of determining my state of ketosis, but it was all I had. When I first started my low-carb, high-fat way of eating, I tested my ketones using urine test strips and was alarmed at first. My ketone level was at the highest it could be. The test strip looked neon purple! I thought I was doing something to ruin my liver and kidneys. However, on further investigation, I realized my body was not fat adapted.
While I was eating low carb high fat, my body was doing its thing in learning how to use fat and ketones for fuel instead of glucose. Initially, the body hadn’t made the necessary modifications to properly utilize the ketones so many of them were being flushed out in my urine, hence the neon purple test strip. Now, several weeks later (about a month and a half), my body has begun to put the proper mechanisms in place to utilize the ketones. Thus, there are fewer ketones being released and flushed out in my urine. I know I’m still in ketosis because I’m careful of the foods that I eat, but as I’ve learned, the further along you go on the ketogenic journey, the less reliable the urine test strips become.
This go around my test strips told me my body wasn’t releasing as many ketones as it had in the beginning. In other words, I took it as my body being more fat adapted. The ketone test strip was in a more acceptable range. During that process, I believe my eyes had become fat-adapted too (if there is such a thing).
Still Making Keto Adjustments
I don’t have this ketogenic thing down pat as yet. My hubby took a week and a half off from work and although we didn’t eat many carbs, we still ate too much food and yes, drank too much. Vodka may not have any carbs and neither does club soda, but the body will stop burning all other fuel sources until it burns the alcohol off first. Alcohol is a toxin and it wants to get rid of it. In the meanwhile, all other fuel consumed gets stored whether it’s fat or carbs. Hence, my stagnant weight loss.
Ok, there was the occasional Bloody Mary 😉
From what I’ve learned, carb-less alcohols such as vodka and tequila do not take you out of ketosis, but they will stop weight loss. Added to that, we ate out at restaurants maybe twice a day. Even though we selected low carb, high-fat meals (well, actually, we had the chef modify the meals to ditch the carbs and double up on the veggies), I’m sure the sauces were not strictly ketogenic. So, weight loss for me has stalled.
Fortunately for me, he’s back to work and I’m back to preparing all our meals and ditching the vodka. I’m also back to my daily exercise routine which took a major hit while he was home from work.
Hmm, just got me to thinking. Let’s see if my vision blurs again as I go back on my strict ketogenic way of eating. Only time will tell. If it does, I’ll make notes here. Honestly, I think I’m over the blurry vision hump, but I’ll check back in a couple of weeks to let you know if it returned.
It’s all about the journey!
9/6/17 Update: No more blurry vision! It seems that my vision has returned to what it was prior to starting keto eating. Hooray!
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I have cycled on and off keto over the last eight years. I know that when I get back on keto, I’m going to get blurry vision for a few weeks. It usually starts about a week into keto, and as Felicia notes, lasts about a month. It’s funny, I’ve never thought to do an internet search about it until I started this cycle. It’s good to know it isn’t only me. Thank you, Felicia for the article; it is a nice read!
Hello Felicia, maybe a few years later of your post, but i just started 100% carnivore diet last monday, cero carbs , by wednesday blurry vision came:( , im 45 never Eye glasses before, not a perfect visión but never have to put eyeglasses, i took a ketosis test i have 1.5 , today blurry visión is getting worst 🙁 , when i use my wife glasses everything gets clear, i Have lost 6 lbs in just 5 days, so i dont want to quit, do you have any advice? Should i ad some carbs? Or wait the Body to respond? Thanks
Sorry for the late response. As you mention, there are two possible solutions to the blurry vision problem. You could add in a few carbs and things should improve (not too many, just a few). However, if you don’t want to add carbs, you can ride it out. Your vision will improve, but it does take time. It took me several weeks before things cleared up.
Thank you for the article. I had very few carbs yesterday and also decided to start intermittent fasting as per recommendations of my doc. By about 1030 this morning, my vision became very blurry. It got better once I ate (avacado and tuna). I was also freezing and I am usually hot blooded! It Will be interesting to see how my body adjusts in the coming days! This is my second time trying this diet and I am super determined this time. My A1C is way too high (11.3) and I refuse to go on inulin!
Thank you for the article! It’s encouraging to keep going know things will eventually normalize 🙂
Thanks for sharing, Amanda.
Stick with it, things will improve!
Thank you for sharing. Just started keto, to shed off Easter weight gain. Now I got this blurry vision and light headedness. I took a protein snack and it went away.
My vision seems to have returned to normal. Although I do notice on some days when I’m extremely low on carbs coupled with not drinking enough water, my vision blurs a bit. I try to make sure I drink enough water to remain hydrated.
Glad the snack works for you.
Thanks for posting this…I am about 7 days into the SKD (standard keto diet), and I noticed some blurry vision which started this past weekend (difficulty reading standard text while surfing the web), at about the 5 day mark into the diet. My vision is normally 20/20, and on occasion, I need readers (I am 46 yo). I am a diabetic, and have been for about 6 years now…I was under tight control for 5 years, and in the last year, my glucose numbers have fluctuated slightly higher (and metformin has less effect at reducing the high numbers) , and overall, my numbers are above where they need to be to maintain a decent type 2 diabetic A1C level. I went on keto to reduce some of my insulin resisitance and see if I could get my numbers back down through dieting and exercise. The vision changes had me worried and I am glad I came across this article… I hope this issue is not going to last for more than a few more days, because I do alot of close up work in an engineering lab, and its been frustrating with varying degrees of bluriness or needing different powered readers to see what I normally can see, crystal clear. Thanks! Todd
Glad the article helped. Unfortunately, for me, it took longer than just a few days. It took more like several weeks for my eyes to return to normal. I’m older than you so it might just be age on my part.
Hope your numbers improve and your vision clears up quickly.
Thanks for the response. I did some research on a bunch of diabetic forums, and it appears that any fluctuations in blood glucose (higher or lower) can cause blurry vision. In some people, this clears up quickly and for others it takes weeks. A few recommendations for clearing the blurry vision problem up a bit quicker are to reduce the carbs you intake at a slower rate so your eyes can more easily adjust to the lower glucose levels in your blood. Many people reported that eating a slightly higher carb intake for a couple days resolved the problem, and a few people waited things out and their blurry vision went away eventually. It’s taken me some effort to get to this point with keto, so I would prefer to wait out the blurry vision thing out, and stay on the diet–I really don’t want to ruin my efforts to get into ketosis. Between this blog and some additional forum research, I feel safe in continuing forward with keto, and it doesn’t seem to be as alarming now after my research. Thanks again.
Thanks for sharing the info. Like you, I didn’t want to increase my carbs and bounce myself out of ketosis. I stuck it out. I’m glad I did because now I feel great. I still use readers but needed them before going keto.
Your comment will help other visitors who aren’t quite sure if they’re causing damage to their eyes by going keto. From my experience and your research, we’re not damaging our eyes, just causing them to adjust to the carb reduction. Thanks again for the update.
Hey, thanks for writing this article! I am on day 6 of a vegetarian keto regimen and my eye sight started getting blurry again (I tried it last month but stopped after day 5 because of the blurriness.). I’m glad that I googled it this time and found your page….I’ll stick it out this time! -Michael
Hang in there! It does get better. Congrats on your keto regimen.
You’ve got some great looking recipes on your site. I’ll have to try a few.
Thank you for this article. I was getting worried about my vision. This has set my mind at ease.
It does get better. Hang in there.
Thank goodness I saw this! Thank you so much. I started keto about two weeks ago and after a few days my long-distance vision became blurry. Very scary. I use reading glasses but never had a problem with the tv or distances. I am type 2 diabetic but am going keto to lose weight and get rid of the diabetes. I have been very strict about carb intake — 6-8% of calories, and I plan and measure everything I eat to the gram. I read that blurry vision is a symptom of low blood sugar, so I wonder if the sudden low-carb diet was a shock to the system. If this blurriness doesn’t go away I am really going to panic. Thanks for sharing this.
It is rather scary for vision to become suddenly blurry. I continue to read and research about ketogenic eating and have found that although the body may quickly enter ketosis, it takes much longer for the body to become fully fat adapted. It could take as long as several months for the transition to take effect. I’ve found that during the adaptation process my vision could change day to day depending on how strictly I adhere to restricted carbs. As you mentioned, I think it is sort of a shock to the system. I don’t think you should panic though.
I saw a video on the Diet Doctor site of a gentleman who, after being keto for an extended period of time, no longer needed glasses. I’ll link to his video, but you won’t be able to view it unless you’re a member.
You seem to be doing well, and as long as you stick with it I believe your diabetes will become a thing of the past. If I find more info on vision and keto, I’ll share it here.
Best of luck to you!
Thank you so much for communicating your experience with the eyesite changes. My eyes have been changing so much and I even had vertigo while driving today in the mountains which I never have had before. I went online to see if other people have this experience and how to relate to the changes best. Also, your frittata looks amazing! Thanks!
Glad my post helped. Can’t say I’ve ever had vertigo, but I did experience a little light-headedness early on. What I found out was I needed to add more salt to my diet to combat that feeling.
Hang in there! I believe things will all even out. BTW, the frittata tasted better than it looked. They’re so easy to make that even my husband made it a couple of times. 🙂
Have you been supplementing electrolytes well? Magnesium (preferably in Malate form) is pretty important for many things including eyes and magnesium deficiency can cause vertigo. I notice if I miss my daily dose. https://goo.gl/images/SuL2P2
Hi, very interesting thread. I came across this because I had some shakiness and anxiety out of the blue when I was driving to work. I realised that the previous day I’d had about 800 calories mostly fat so very very few carbs, maybe 5g and hardly any protein. I’d skipped breakfast too. I think it was a hypoglycemic incident. I ate a green apple! And it slowly went away. After a month of keto I guess my glycogen store is mostly gone. I’m not diabetic by the way.
So I’ve had some side effects from the Keto diet which when I look, I see others had also had, though some aren’t massively publicised.
Don’t get me wrong I love the keto diet/lifestyle which I’ve been doing about a month. I love the weight loss and I love the ‘filled with sunshine’ feeling. I had to read up and take more salt because I was definitely getting low on sodium and it had a weird effect on my mood. When I took salt, I got happy again. Then the blurry vision. Definitely noticed it, just thought I was getting older and eyes were getting worse, but it’s great to see there’s a physiological reason in that eyes need glucose.
After a lifetime of carb addiction, it’s going to take a few weeks for my organs to adapt, I’m producing good ketone levels 2.6 mmol, but my body is peeing lots of them out currently until it adapts.
Glad to see the blurry vision thing improves 🙂
I’ve found that it takes my body some time to adjust to keto. The blurry vision was just one way of adjusting. Your mentioning the shaky feeling is another adjustment I had to make. Like you I needed to add more salt to my diet.
Overall, I enjoy eating keto, but it does take a little time to get used to it.
You seem to be doing well. Hang in there!
Same story. A week and a half into LCHF and I’m having trouble reading a book with fine print. I’m 54 and weigh 300lbs. I’ve varied from 40 to 100g of carbs daily, so I’m a long way from the coveted 20g but I’m easing into it. I’ve lost 15 lbs. and I think this is a lifestyle change I can and really need to maintain. I haven’t been testing fo ketones, yet, and now probably won’t test for a couple more weeks. Good to know the blurriness goes away. I’ll bet the poor focus is due to the glucose deficiency, since I’ve heard the glucose supports quick movements, like the focus of the eye.
Congrats on your 15-pound weight loss, Mike. I guess even with easing into it, the change in glucose still makes things a blurry.
I wish a medical professional with a real explanation for the blurry vision would stop by and give us the lowdown. In the meanwhile, it’s good to know it does go away.
Keep up the good work!
Thanks so much for this blog post. I’m one week in and have had blurry vision the last two days. I’m glad to hear there’s an end in sight (no pun intended). 😉
Hang in there, Rob. It does get better.
Thanks for the blog, I have been on Keto for a week now and have been experiencing blurred vision, this freaked me out. There is not much info on this online, to read your blog reassures me that I will eventually recoup. I never had any vision problems earlier, I am 48 years old, after the low carb diet I cannot focus on my eyes while using my phone or compute. I am a web designer and I need perfect vision to execute my work. Thank you so much for writing this, also please let me know if you have any other threads relating to this problem. Thanks again
I feel your pain. When my eyes started blurring I searched and searched to see if I could find anything online about it. Most of the information I found talked about vision and diabetics. I’m not a diabetic but was still concerned. I figured my vision blurriness had to do with going keto so I decided to ride it out. Boy, was it a rough go. It as especially weird wearing two pairs of reading glasses when in the past only one did the trick. It took about a month or so for things to clear up, but they did, thankfully.
I work online quite a bit and understand your frustration. It takes a while for the body’s internal mechanisms to catch up with the carb adjustment. If the blurriness is really getting you down, increase your carbs and then very slowly reduce them again. Hang in there, things will get better.
Sadly this is the only post on the keto blurry vision topic I have. It’s strictly from my own experience. As we both know, there isn’t a whole lot of easy-to-find information online about this condition. I’ll continue to search and if I find more, I’ll share the info.
I read this with great interest! I noticed my vision was becoming increasingly blurry. Only thing I was doing different was eating keto. I’ve been eating keto for a week and a half and noticed the vision problems first this past Sunday. As I was grocery shopping I noticed how hard it was to read the ingredients. I look far away and usually that refocuses my eyes. This time it didn’t, and I was scared! I cannot go much longer with this reduced vision! My job is dependent on me seeing tiny numbers and inputting them in a computer program! My carbs for pretty much the entire 10 days were under 20 grams. Most of the time, closer to 10! I think that might be a big cause of it. So I redid my macros to have a 10% carb intake instead of a 5%. Hopefully that will correct the problem. I have lost 8 pounds so far and 2 1/2″ off my waist! So hurray for that! Keto on!
First I want to say congrats on your weight loss and your reduction in inches. Keto has so many benefits, but I’m sure you’re aware of that.
The blurry thing caught me off guard at first. I started to double up on my reading glasses in order to see as I had prior. Wearing two pair of glasses looked weird, but a gal’s gotta do what a gal’s gotta do.
My carb intake was about 20 grams a day. Some days less. I found that on the few days when I increased my carb intake above 20 grams, my vision improved. However, I had the sneaking suspicion that if I could ride out the blurry storm that eventually things would get back to normal. They did but it took me a few months. It could be because of my age, but I’m not sure.
I’ve read that a drastic change in the blood sugar levels will cause a change in vision. From what I’ve read it stays that way until the body adapts. Not wanting to go in and out of ketosis to prolong the blurry vision episode, I tried my best to keep at 20 grams or below. It was trying at times (most of the time), but I believed there was a light at the end of the tunnel.
In the end, the whole blurry vision episode was worth it. Recently I saw people that I hadn’t seen in years. One of my relatives kept asking me, “Are you holding your stomach in?” I wasn’t, but that tells me that the reduction in my waist circumference is noticeable. I have to thank keto for that. 🙂
Your situation is different because you have to read small numbers. To be honest with you, sometimes I had to use a magnifying glass to read small numbers. I’m sure that’s not something you want to do on your job, but it does help.
I believe reducing your carb intake slowly might prevent this. I’m not sure because I didn’t use the slow approach. I’m thinking that a slow reduction will give the body a chance to adapt. That way your vision might not temporarily tank.
It’s going to be a balancing act for you. Eventually you’ll figure out the ratios that work for you. I’m very interested in your progress. Please keep in touch and let me know how things are going.