Seasickness - a conjecture

I suffer mildly from motion sickness - rarely sick, but I often feel queasy in the back of a car, and I can't go below for any time when at sea. I got varifocals for the first time this year, and started to feel ill more often, but didn't put two and two together until chatting to someone on a train. She experienced the same thing, and was told it was the varifocals, as they have a narrower in-focus band than normal specs.

So, yes, I agree with you - varifocals make seasickness worse.
 
colind3782 said:
Only been seasick twice, once when I was very drunk off Thailand and then on the Irish ferry when everyone else was being sick around me.
Click to expand...

Ahh the old "mail boat"? ...blokes washing down massive greasy breakfasts with a few pints of the back stuff :very_drunk: ....and then...

...I'd have thought being short sighted on deck was a blessing back then!
 
I felt queasy once on a boat (tied to the pontoon) the day after I had my new varifocals. I had difficulty judging step heights. Within a couple of days I had learned to turn my head instead of simply swinging my eyes. Problem solved.

Re hearing impairment, my wife has started to be affected but her sense of balance was never much good. If you so much as wiggle a glass that is half filled with water in front of her she gets very close to puking. Fortunately for me I enjoy sailing single-handed.
 
Sadly I'm very easily motion sick in boats, cars and trains....also very shortsighted and bad astigmatism, so another one scuppering your theory.

The biggest factor as far as I'm aware in determining seasickness is sex......or rather gender, so I don't create the wrong impression! Women much more likely to suffer. Possibly because women are genetically programmed to be very sensitive to things which can cause nausea ....eg poisonous food to ensure they protect an unborn baby from bad food. Just a theory...
 
I think Amulet may be onto something, as one of the minor contributory factors to seasickness; I have just had to start wearing long range driving glasses and find my peripheral short range vision with them on quite a disconcerting shift, enough to make me feel slightly off balance.

Haven't tried them sailing yet and I don't think they'll make me sick as I don't usually suffer, but I can imagine it getting to some people.
 
Vanilla said:
The biggest factor as far as I'm aware in determining seasickness is sex......or rather gender, so I don't create the wrong impression! Women much more likely to suffer. Possibly because women are genetically programmed to be very sensitive to things ....
Click to expand...

Hmm, I sometimes think my other half is genetically programmed to be sensitive to my mere presence :D
 
I researched seasickness for a blog post some years ago and at that time there was a theory that covering one eye prevented seasickness.
Also, wearing one ear plug prevented seasickness.
I couldn't find research results for wearing an eye patch and one earplug, however.
The theory is that the confusion between what your eyes and what your ears are telling your brain causes vomiting. However, it only works in 3D, so covering one eye doesn't provide enough information to confuse the brain.
Maybe this is why pirates wear eye patches?
 
The basic theory for motion sickness remains that it is provoked by a mismatch between positional information coming from the ears and the eyes. There's a bit more to it, but that's the basics. Any motion environment can cause it, including weightlessness. Alcohol interferes with the balance organs in the ears, which is why even small amounts of alcohol the day before can increase the likelihood of motion sickness on the day after. In the RAF IAM's desensitisation programme for student aircrew with motion sickness even a half pint of beer was enough in the most sensitive subjects.

There's enormous individual variation, but the physiology laboratories with the appropriate equipment can make anybody with normal inner ears sick. Some forms of ear disease create immunity to motion sickness, but they also have an adverse effect on trying to walk in a straight line.

Three things matter: sensitivity, adaptability and retentivity.
Sensitivity - some people are very sensitive and get sick when the land disappears over the horizon, others can cook a three course meal in a 25-footer in a gale without feeling even queasy.
Adaptability - some people feel sick throughout a voyage, others rapidly get their sea legs and stop feeling sick.
Retentivity - some people adapt well, but on going on another trip a few days or weeks later feel sick again. Others retain their adaptation and have no sickness on further exposure.

The ideal sailor has low sensitivity. The next best thing is a sailor with good adaptation and retention. (Horatio Nelson failed on all three counts, but he became a national hero.)

There's no association with impaired visual acuity and I don't recall there being any evidence that women are more sensitive than men. It would be perfectly reasonable to suggest that starting to use varifocal lenses could provoke motion sickness in somebody who is sensitive.

PS. There's no evidence that eye patches make any difference, and not only do ear plugs not work, there's no way they could work. It's the gravity and rotation sensors in the inner ear that deal with positional information.
 
Last edited:
It is a riddle. I don't suffer from it, neither does SWMBO. To her credit, she prepares hot meals in the galley in a heave ho without batting an eyelid. But in discussion with a lot of people who suffer from it, it seems the affliction is triggered in different sufferers for different reasons. One chap I talked to had never suffered from it in years of sailing until one day he had to do some work in the engine room in rolly conditions. Not only was he seasick on that occasion but never recovered his immunity to it. It must have been the smell of diesel.
A study was carried out and 35 % of respondents were never or seldom seasick and the other 65 % reported they were seasick nearly all the time. Of the 65 % about a quarter reported that eventually they got their sea legs.
Additionally the study found three possible causes. 1 not warm enough. 2 tired. 3 wrong food (greasy) or alcohol before sailing and the fourth is the oddest; lack of hydration. Apparently not having drunk sufficient water before sailing could prove a contributing factor. Nowt so strange as folk, as they say.
 
I know studies have reported female to male seasickness in the ratio 1.7 : 1 Hormonal differences have been postulated by some researchers as the reason, but it could simply be that women are more likely to admit to feeling sick than men! also more common in people who suffer migraines and women have a much higher incidence of migraine than men.
 
VO5 said:
One chap I talked to had never suffered from it in years of sailing until one day he had to do some work in the engine room in rolly conditions. Not only was he seasick on that occasion but never recovered his immunity to it. It must have been the smell of diesel. <Snippage>
A study was carried out and 35 % of respondents were never or seldom seasick and the other 65 % reported they were seasick nearly all the time. Of the 65 % about a quarter reported that eventually they got their sea legs.
Click to expand...

Interesting comments. I do suffer from debilitating seasickness, and can identify with the points raised above. As a general rule, on my own boat I'm fine, but ensure I acclimatise early in the season, by being below decks on the mooring for a protracted time. If I sail on other types of boats with a very different sort of motion, I will still be hit. I usually take Stugeron for strange boats or longer passages - although that can back fire, as it did on a 36 hour trip in a 42'cat to Ireland a few years back, when after the 2nd Stugeron dose I could do nothing but sleep. I took the next dose, but spent 12 hours throwing up lying on the cockpit floor. However, after 24 hrs I'm always over it. The one strange episode was an Ocean Youth Club trip in the early 70's when we had powdered oxtail soup for lunch, which made a second appearance later. I still can't smell that without feeling sick, afloat or ashore.

Best cure for me is to get below, bucket in hand, and lay down... The bucket is mainly needed for the "getting below" bit...
 
Last edited:
Amulet said:
I just got varifocal spectacles and they made me feel slightly seasick - wearing off now.

Seasickness is sometimes attributed, at least in part, to a disconnect between what the eyeball sees and the balance sensors feel.

I know a number of lucky people who seem immune to seasickness. In all cases (but one) they have crappy vision corrected by hefty specs since childhood.

Might it be that they are used to screwed-up vision and balance relationships and so resistant?

And also... we have seen these weird glasses that help with seasickness (?). Maybe we should get specs that make you seasick until you get over it while you ashore. Puke at work rather than on your boat.
Click to expand...
The clue to the cause of the malady is in the varifocals, the accepted wisdom being that if you look out of the boat, with the horizon in view, you will keep seasickness at bay, whereas, if you are focussed on something closer you are going to feel queasy. Obviously if your are looking at something close e.g. instruments, or some manual task, it will be viewed through the lower part of the lens, but the effect would be the same, varifocals or not.
 
Last edited:
SWMBO wears varifocals and is sea-sick upwind - I wear varifocals and am not sea-sick, but don't eat much when at sea, so perhaps I am to some degree?

We have evolved a strategy for dealing with our afflictions, well most anyway, but am not entirely convinced about the "lens" angle - surely it's more to do with the eye/balance relationship and the way the brain interprets the messages, possibly conflicting, being received - though do agree about the smell of unburnt Calor gas.
 
Gladys said:
Interesting comments. I do suffer from debilitating seasickness, and can identify with the points raised above. As a general rule, on my own boat I'm fine, but ensure I acclimatise early in the season, by being below decks on the mooring for a protracted time. If I sail on other types of boats with a very different sort of motion, I will still be hit. I usually take Stugeron for strange boats or longer passages - although that can back fire, as it did on a 36 hour trip in a 42'cat to Ireland a few years back, when after the 2nd Stugeron dose I could do nothing but sleep. I took the next dose, but spent 12 hours throwing up lying on the cockpit floor. However, after 24 hrs I'm always over it. The one strange episode was an Ocean Youth Club trip in the early 70's when we had powdered oxtail soup for lunch, which made a second appearance later. I still can't smell that without feeling sick, afloat or ashore.

Best cure for me is to get below, bucket in hand, and lay down... The bucket is mainly needed for the "getting below" bit...
Click to expand...

I find it interesting that after 24 hours you are able to get over it.

I am going to make a suggestion to you, though it may seem arcane.

My suggestion is that you prepare yourself 3 days before you go to your boat whether you intend to sail or just remain in port. Avoid alcohol and instead for these three days drink plenty of bottled water and get yourself properly hydrated. Only water can get you hydrated, not tea, coffee or fizzy drinks. Just try it, see what the results are, and let us know.
 
VO5 said:
I find it interesting that after 24 hours you are able to get over it.

I am going to make a suggestion to you, though it may seem arcane.

My suggestion is that you prepare yourself 3 days before you go to your boat whether you intend to sail or just remain in port. Avoid alcohol and instead for these three days drink plenty of bottled water and get yourself properly hydrated. Only water can get you hydrated, not tea, coffee or fizzy drinks. Just try it, see what the results are, and let us know.
Click to expand...

I am an inveterate water drinker... so I don't think that would do it for me.
 
andygc said:
...There's no association with impaired visual acuity and I don't recall there being any evidence that women are more sensitive than men. It would be perfectly reasonable to suggest that starting to use varifocal lenses could provoke motion sickness in somebody who is sensitive.....
Click to expand...

This is all very interesting, can you tell us where this study is published? It sounds very comprehensive and would make interesting reading for all of us.

N.B. My original conjecture certainly didn't imply direct association with acuity but rather with lifelong wearing of spectacles (probably for distance vision I guess) which of course would be a correction for optical loss of acuity. The anecdotal comments on the thread provide scant, if any, support for my original brainwave, but a study of all the factors you mention would be interesting in any case. Like you, I'm pretty sceptical of hard-to-explain ideas, like the use of earplugs, but I'd be hesitant to be so bold as to suggest that there's no way they can work. There are lots of hard-to-explain weirdnesses in the human system, e.g., why does rubbing your eyes lower you blood pressure? To the best of my knowledge no-one knows.
 
Gladys said:
I am an inveterate water drinker... so I don't think that would do it for me.
Click to expand...

Yes, I take your point. I am also an inveterate water drinker, but it is not what I mean.
What I mean is a regimen of water drinking three days before going aboard whether one is thirsty or not, rather like the systematic intake of a prescribed medicine. Bottled water morning afternoon and night, then see what happens on day 4 when you step aboard, is the nature of the exercise. I know of one skipper in the Caribbean who will not sail with his crew until they are all properly hydrated, so arcane as it may seem, there is lot to be said for it.

The other considerations also should not be neglected, such as eating greasy food prior, not being warm enough and being tired. All of these are contributory factors it seems.

Then eyesight, according to this thread also seems to impart an effect, but I have no experience of that, so cannot comment.
 
You must log in or register to reply here.

Share this page

Top