Over the years, a screw will decide to back out. When I screw it in, it will usually do it again in a couple of days untill I put a dab of glue or lock-tite on the damn thing. How can a screw back its way out? This is common on machinery which vibrates, but the last time I checked I don’t have any vibrations going on in my head. Anyone else have the same problem?
Yes, I have that problem. I think it’s to do with not handling the glasses with enough care, putting them on slightly wonky, and the like. Your head gets a fair bit of movement during the day - perhaps it’s a cumulative effect of multidirectional movement.
I don’t seem to have this problem with my eyeglasses. Then again I only wear mine for driving, lectures, and to see distances. I normally take them off while at work or while eating.
I would think that heads do a lot of vibrating. For example, while eating the jaw muscles cause glasses to move slightly. Also there is stress whenever you take them off and put them on again. Improperly fitting glasses would do a lot more moving than properly fitted ones. I noticed when I lost weight, my glasses didn’t fit me right and I needed to get them readjusted.
Then there is the possibility you might have glasses that were improperly manufactured. I paid big bucks for my Calvin Klein frames and I haven’t had a single problem with them. If a manufacturer created the screw improperly, then you could have more problems than average.
If I had problems with my specs I would address it to the shop I bought the glasses from. They will often adjust glasses for free and could fix the glasses so they wouldn’t come apart.
I’ve also had that problem at times. I can only guess it’s the motion created when you clean the lens which could have the effect of loosening the screw over time. Actually, one of my lenses fell off on a couple of occasions and I didn’t necessarily have the microscopic screwdriver handy at the time. Bit of an annoyance.
Glue or lock-tite can be a solution as long as you don’t intend to keep the same frames when you get new glasses. You might do too good a job, if you know what I mean. A slightly bigger screw could do the trick.
My WAG is the action of folding and unfolding the glasses. If you look at it, unfolding the right arm (from the wearer’s perspective) could turn the screw counterclockwise, while folding the left arm does the same for the screw on that side. I don’t know why the apparently equal distance covered between unfolding and folding the arms would result in a net change in the screw’s position, but we’re talking eyeglasses here, not precision engineering. Various imperfections in the screw or the threads may push the screw more in one direction than the other.
40 years of empirical observation here: People (like me) who put their glasses on with two hands and with great care, not flipping the sidepieces too much, do not have a problem with screws that fall out. People who grab their glasses with one hand and slide them on (like the Better Half and Bonzo), flipping the sidepiece out (you know what I’m talking about), have problems with the screws falling out. Therefore, I conclude that it must have something to do with the sidepieces moving back and forth, which would cause the screws to back out.
Moral: put on your glasses with two hands, carefully, the way the optometrist showed you, and don’t argue.
You’re right. I’m trying to be good with my new glasses and put them on carefully with two hands. Let’s see how long I last.
With frames older than a year or so just tighten up the screws when you give them the weekly deep cleaning with alcohol and q-tip. Keep a repair kit in the glove compartment and a couple of small safety pins around.
If your frames are newer, take them back where you got them and ask for help. They might be able to toubleshoot out a potential problem, at least they will clean and re-fit them.
There are two factors (at least).
(1) The screws are the integral part of a hinge and therefore subject to rotational friction forces that make them want to turn.
(2) It’s easier for friction to loosen a screw (releiving force) than tighten it (applying force).
What I don’t understand is why they haven’t found a way yet so they don’t come out? Science surely must have a way by now.
Oops! My bad. Just reread the subject line and realized we were talking about the lense screws, not the ear piece screws. Sorry…
Actually the answer is probably the same, except the rotational forces are probably due more to flex of the whole eye piece assembly. This flex will certainly be more prominent with people who are less careful in how they put on and take off their glasses.
It happens every few months and there is no answer and it doesn’t matter how much you spend on them. I just got another pair and this one the lens flew out after two days, so I whent back to the old pair. It may be true that if you are a very linear, accountant type of person and use both hands and so on as one above suggested, all will be well. Therefore there may be an answer: just get born in the first place with a careful, painstaking, step by step, exacting,
calm disposition and you’ll have no screwing problems. As for me, I am still interested in the physics of a screw backing itself out and I suspect foul play by the manufacturers. Who are the same manufacturers who make computers, by the way, so that they don’t work unless you keep turning them off and on, and which are slow while their adherents keep saying they are fast. Although I do like the internet a lot. Now if it only worked when you wanted it to and if only it was much faster!
No, no! It is NOT the screws which hold the sidepieces on. It is the screws which clamp the lenses in. Movement of the sidepieces should not affect them.