[newfie ghost]

Do you see variation in the quality of your image from time to time? I guess this reflects changes in "seeing" and minor biological changes. Sometimes my vision is sharper at different times of the day or depending upon what I eat. From stargazing I know this does vary with the atmosphere. Anyone else notice these differences?

[brocknroller]

Sample variation of the eyeball or the brain or the entire opto-brain system? Whatever it is, yes, I do experience changes in visual perception from day to day, hour to hour.

Some days, it's totally fruitless to use binoculars for me. My eyes/brain are just not up to the task. Other times, even my lesser quality bins impress me.

However, I have never kept a food/drink diary to see if what I eat or drink affects this, but it sounds like a great OCD idea. :-)

I do know that eating makes my hands shake more because my heart is beating harder/faster. While I assume this is due to my heart getting the blood from my periphery to my innards, there could be other reasons. i've read that eating meat makes your heart beat faster. could be vegan propaganda, but i will test it out sometime.

certainly, avoiding caffeinated beverages helps improve the view by steadying the image, but as to why the image seems easier to "hold" some times of the day than others or some days and not others is a mystery that perhaps Ed, our visual expert, could help unravel. maybe my cones and rods have a different sleep cycle than my brain.

broca's brain

[14Goudvink]

In Chinese medicine the stomach and eyes are connected. The stomach meridians run around the eyes.

[James Bean]

First thing in the morning my eyes are reluctant to focus consistently. For example, if I use binoculars the previous day and finely adjust the right eye dioptre, it's no guarantee that it will still be exactly correct next morning. I'm acutely conscious that as time passes I'm not getting any younger (manifested by such vision variations, not to mention other symptoms) and although I still don't wear glasses, my near-focus ability now seems to worsen daily. I have the consolation that there's no point in my buying the best optics available, if I could afford them, because my eyes wouldn't appreciate the difference...

[Larry Lade]

An interesting thread!

I do experience some of the symptoms mentioned above, but mostly attribute it to my advancing years. I am no "spring chicken" anymore.

[newfie ghost]

I never noticed the changes until I used glass extensively. Not saying the glass caused it but it has made me pay close attention to detail. To complicate the story, I also noticed that my eyes see color somewhat differently. My left eye sees somewhat brighter and richer colors than the right. First i didn't want to believe this, but it is true. I discovered this after i got my spotting scope and noticed a slight difference between each eye.

[LPT]

I, too, have noticed variations in how my eyes focus sometimes only from one day to the next but also sometimes even during the course of a 1 or 2 hour walk. The fine focus in my left eye, in particular, seems to shift from time to time. I agree with most of the explanations stated previously in this thread about why this happens, but today I noticed one other cause which has to do with field curvature. With a lot of binoculars I think older eyes will perceive field curvature closer to the center of view than will younger eyes which are better able to focus it out. So this being the case, what I noticed today is that if I focus at infinity while viewing directly in the center of field, that focus will slightly change if later my view shifts to the upper of lower edges of the central field of view due to field curvature. Likewise if I focus the binocular while not viewing perfectly directly in the center of field, the view could lose focus if later I view directly in the center. Of course, the likelihood of this happening depends a lot on the ability of your eyes to focus out field curvature, the amount of field curvature the particular binocular has and how often your view strays from the exact center of field.

[lulubelle]

This thread makes me feel much better!

I had a severe acute onset of vertigo in 2008 and my vision has been wonky ever since - at least on some days. Not to mention the over 40 yrs issue!!!! Sometimes it is a day to day change in visual acuity, sometimes it is hourly, as mentioned above. I hadn't heard anyone else complain of this issue, so I assumed it was more the residual vertigo symptoms that were at the heart of the issue (it totally screwed up my vision for about 6 months or more - I almost quit birding because of it.) Left eye is worse by far when I have trouble. On some days the view through my bins (binoculars, glass, whatever you want to call them!) is trouble free & beautiful! Very frustrating!

Nice to know I am not the only one who notices these types of visual changes out in the field!

[Steve C]

At 64, I'm beginning to see a little change in my right eye at certain times and conditions. Usually in gray dull days or twilight, I am finding I sometimes need to tweak the diopter for the right eye. Not much and not always even in the same sort of conditions. If I'm really tired, or maybe have a headache, it is worse.

[brocknroller]

Originally Posted by lulubelle

This thread makes me feel much better!

I had a severe acute onset of vertigo in 2008 and my vision has been wonky ever since - at least on some days. Not to mention the over 40 yrs issue!!!!

Are you taking your calcium and vitamin D? Okay, we won't mention the "over 40" issue, again. :-)

You might want to read my post (#13 - scroll about half way down) on the thread below to see if you have the same inner ear problem I do. There are techniques that help with it.

http://www.birdforum.net/showthread.php?t=226304

Durante degli Alighieri

[lulubelle]

Originally Posted by brocknroller

Are you taking your calcium and vitamin D? Okay, we won't mention the "over 40" issue, again. :-)

You might want to read my post (#13 - scroll about half way down) on the thread below to see if you have the same inner ear problem I do. There are techniques that help with it.

http://www.birdforum.net/showthread.php?t=226304

Durante degli Alighieri

Not to hijack a thread over vertigo issues, but I did try several exercises and none really seemed to work. I really thought I had a stroke, but many CT's/MRI's all seemed to dispel that issue. I would think one thing and say another for the longest. My vision was well screwed for 6 months or more. It took a good 3 year before I stopped feeling "wobbly" continuously - looking up was interesting to say the least; walking into shadows while out birding or into a store with bad lighting could make me off balance completely. My depth perception was completely off .... They ruled out every disease process, including a tumor...idiopathic in nature. Was so miserable at one point (off work for a month spinning), I would have been happy to undergo a treatment that would have caused deafness in my left ear, as opposed to continuing to spin. I personally think it was because I got a bit of water in my left ear one day, for months had staggeringly sharp pains in my left ear and then pow, vertigo.

Looking through binoculars was an issue, not with rolling ball effects, but simply the way my brain processed what I was seeing, along with my constant visual changes (not diabetic either). I practically had to learn bird songs all over. Storms used to really make me have bad days - hard to think on days when I felt really wobbly, staggered about like a drunk (always spun to the left and during my recovery I would drift to the right when walking!!!). My coworkers got very used to grabbing me to stabilize me. Thought perhaps it was all gone till about 3 weeks ago and then while I was out birding, positional vertigo hit...... My Dr. says after an severe acute onset like mine, when it returns it is usually positional. Now seems to have abated, but makes me panic.

Any way, vertigo aside, still makes me feel better to know there are other like me who at times struggle for the good view! BTW, I suck at taking my meds, but yes am on the calcium & Vit D track!!!

[lulubelle]

Sorry - TMI!

[barshnik]

I've been diabetic (type 1, insulin dependent) for 30 years. My vision changes substantially from day to day, hour to hour, sometimes minute to minute depending on blood sugar levels.

Low blood sugar (less than 60) results in a visual fluttering (almost like a fluorescent bulb sensation), as well as blown out whites.

High blood sugar (over 280) seems to cause an overall darkness in an image, and lack of contrast.

Any other type 1 diabetics out there with weird visual changes with blood sugar levels that affect your bino use?

John F

[John Dracon]

Laura - First, sorry to hear that your vision is causing you some problems. Second, have you experimented with different powers and exit pupils to see if that would help? Does sitting down make a difference? I find standing and looking through binoculars tends to give me vertigo. Are your binoculars perfectly collimated? Some people cannot accommodate less than perfect collimation. I'm using a solid rest more and more.

Also, for what it is worth, different models for whatever reason give me a more relaxed feeling to my eyes than others. And they are not necessarily the latest models. I'm one of those people whose vision cannot handle plastic lens. They must be made of glass. My opthamologist tells me there is no difference in refraction, but I can clearly see the difference in visual acuity. Anyway, I hope your problems with balance go away and that you can return to your obvious passion for birding.

John

[brocknroller]

Originally Posted by barshnik

I've been diabetic (type 1, insulin dependent) for 30 years. My vision changes substantially from day to day, hour to hour, sometimes minute to minute depending on blood sugar levels.

Low blood sugar (less than 60) results in a visual fluttering (almost like a fluorescent bulb sensation), as well as blown out whites.

High blood sugar (over 280) seems to cause an overall darkness in an image, and lack of contrast.

Any other type 1 diabetics out there with weird visual changes with blood sugar levels that affect your bino use?

John F

Sorry to hear about how your diabetes affects your eyesight. I've read about diabetes affecting eyesight, but only over time and only if it isn't well controlled. I had no idea it could affect your vision minute to minute or so severely.

I have had low blood sugar. Never noticed any changes in vision as a result, but it has given me the shakes, which does affect my ability to hold a bin steady. In such cases, a carb load will straighten out the shake.

[brocknroller]

Originally Posted by lulubelle

Not to hijack a thread over vertigo issues, but I did try several exercises and none really seemed to work. I really thought I had a stroke, but many CT's/MRI's all seemed to dispel that issue. I would think one thing and say another for the longest. My vision was well screwed for 6 months or more. It took a good 3 year before I stopped feeling "wobbly" continuously - looking up was interesting to say the least; walking into shadows while out birding or into a store with bad lighting could make me off balance completely. My depth perception was completely off .... They ruled out every disease process, including a tumor...idiopathic in nature. Was so miserable at one point (off work for a month spinning), I would have been happy to undergo a treatment that would have caused deafness in my left ear, as opposed to continuing to spin. I personally think it was because I got a bit of water in my left ear one day, for months had staggeringly sharp pains in my left ear and then pow, vertigo.

Looking through binoculars was an issue, not with rolling ball effects, but simply the way my brain processed what I was seeing, along with my constant visual changes (not diabetic either). I practically had to learn bird songs all over. Storms used to really make me have bad days - hard to think on days when I felt really wobbly, staggered about like a drunk (always spun to the left and during my recovery I would drift to the right when walking!!!). My coworkers got very used to grabbing me to stabilize me. Thought perhaps it was all gone till about 3 weeks ago and then while I was out birding, positional vertigo hit...... My Dr. says after an severe acute onset like mine, when it returns it is usually positional. Now seems to have abated, but makes me panic.

Any way, vertigo aside, still makes me feel better to know there are other like me who at times struggle for the good view! BTW, I suck at taking my meds, but yes am on the calcium & Vit D track!!!

I can understand how the world going topsy turvy would make anyone panic (even chickens!).

Another tip is to stay away from salt. Salt causes fluid to build up in your inner ear and could make your condition worse, it does for me.

You would think that an IS bin might help since it stablizes the view, but actually I think an IS bin would make it worse. Even before I had the labyrinthitis, I would have to sit down while using a 10x30 IS (more so with one sample than the other, which had better stabilization). Watching the moon "swim" around the field of view made me feel nauseated. So I would stay away from IS bins with your condition.

Positional vertigo can come about from crystals within the ear free floating in the inner ear fluids. When they "touch down" on the cilia, they give them a false signal that the position of your head has changed and the balance responds accordingly.

If the doc has no workable solution for you, keep experimenting with what works best. For example, if I move my head down and to the right suddenly like I do sometimes when I bend over to look out the window, that will trigger vertigo. So now if I'm looking for a bird in the trees in the backyard, I open the top window so I don't have to bend my neck to the side.

I can also understand how walking into the shadows can throw your balance off, because like me, your balance is dependent on visual cues. Same thing happens if I'm walking and I look up at a clear blue sky (no visual cues, plus there might be some "positional vertigo" too). You learn what you can do and what you can't as time goes by.

You didn't say what meds you take. I took Dramamine when my vertigo acted up. But my best assurance is to keep to a salt restricted diet. I also do nasal cleansing to clear out the sinuses and take Nasonex to prevent nasal/ear inflammation.

[ronh]

Splitting close doubles with binoculars is a hard test of vision, and lamentably, a passion.
My eyes do okay unless I have strained them at work, then they're a mess. When all else fails, a 4mm exit pupil is usually agreeably sharp. Lord knows, I'm lucky at 61.

My sympathy for those with real problems. Just keep finding a way.
Ron

[lulubelle]

John - thanks for the kind thoughts & advice on collimation. Have tried a few different bins and some are certainly easier to look through than others - less of a frustration on visually interesting days. Age & disease processes can certainly play havoc with birding - as if trying to memorize the calls & field marks of over 700 species isn't enough!!! Or splitting stars as in Ron's case! (Something I would love to try by the way)

Sir Brock - tried to reply, but your mailbox is full!!!

[absolut_beethoven]

Originally Posted by lulubelle

John - thanks for the kind thoughts & advice on collimation. Have tried a few different bins and some are certainly easier to look through than others - less of a frustration on visually interesting days. Age & disease processes can certainly play havoc with birding - as if trying to memorize the calls & field marks of over 700 species isn't enough!!! Or splitting stars as in Ron's case! (Something I would love to try by the way)

Sir Brock - tried to reply, but your mailbox is full!!!

Sorry to hear about your vertigo, my wife suffers from it occasionally for seemingly no rhyme or reason.

I often wondered how come when I reached age 40 sometimes my vision was better than 20/20, just like when I was 21, and some days it wasn't. And then I befriended a guy in the optics business (seamless bifocals is his specialty), he explained to me that is when most people's vision starts deteriorating with your close focal acuity being the first to go.

In fact he pointed out that after the age of 40 you lose approximately 1" of close focus every year. Hence the reason that most people 50 or older need reading glasses.

Just remember that sudden jerky movements will contribute to your vertigo. Slow and easy is the way to do things.

On a related note, because I'm a watchmaker and use my eyes extensively every day, I really appreciate the few optics out there that give me a nice relaxed view. Not too many binos and microscopes fall into that category.

I have a feeling that certain distortions are more disturbing for the brain to correct than others so I can comfortably look through my daughter's cheapo Nikon SHE binos but have a hard time with others costing 3 or 4 times as much. The expensive Nikon Venturer being one of the most uncomfortable that I have ever looked through, and yet many people loved that model.

Who knows the exact reason, all I can do is report what see and how it makes me feel.

[brentwood]

I have a lot of military type binoculars with individual focus. Over the past 10 years I have noticed that I always have to refocus these binoculars from day to night . I never notice it with a CF model as I tend to twiddle with the focus wheel as soon as I pick them up.
BTW I have picked up quite a few of these IF models in Pawn & Junk stores for really low prices marked 'as is' and found one side to be turned all the way in & the other side all the way out. I think they sell them off cheap as they think the focus wheel has fallen off!

[John P]

Originally Posted by newfie ghost

Do you see variation in the quality of your image from time to time? I guess this reflects changes in "seeing" and minor biological changes. Sometimes my vision is sharper at different times of the day or depending upon what I eat. From stargazing I know this does vary with the atmosphere. Anyone else notice these differences?

I've certainly noticed that on some days things just aren't as clear as I'd like them to be, more often than not I'll be birding with my wife and when I check with her she'll agree; so I've always put it down to atmospheric influences.

It doesn't occur that often, some days are obviously gloomy or misty or too hot and views are going to be compromised, but there are occasional times it happens when I'm not expecting it.

[newfie ghost]

Originally Posted by brentwood

I have a lot of military type binoculars with individual focus. Over the past 10 years I have noticed that I always have to refocus these binoculars from day to night . I never notice it with a CF model as I tend to twiddle with the focus wheel as soon as I pick them up.
BTW I have picked up quite a few of these IF models in Pawn & Junk stores for really low prices marked 'as is' and found one side to be turned all the way in & the other side all the way out. I think they sell them off cheap as they think the focus wheel has fallen off!

Interesting. What power are your IF glass? Are they Steiner? Are they tedious to use?

[brentwood]

I have several IF, some WW2 Zeiss, Bausch & Lomb, Broadhurst & Clarkson and then some more modern Fujinon, all 7x50, I use them for the night sky. I also have a Steiner 8x30 and a Leupold 9x35, that I rarely use. I think they would be awkward for birding.