{"items": [{"author": "Kathleen", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693326650712", "anchor": "fb-693326650712", "service": "fb", "text": "Either your glasses might sit better on a different part of your nose, or sometimes it's because you're farsighted and those are reading glasses.", "timestamp": "1413828162"}, {"author": "Dana", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693327234542", "anchor": "fb-693327234542", "service": "fb", "text": "Mine just won't stay all the way up there, no matter how I try!", "timestamp": "1413828540"}, {"author": "Perry", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693327499012", "anchor": "fb-693327499012", "service": "fb", "text": "Yup - they just slide right off, thanks to our natural oils that kind of build up on the nose.  Of course the closer I bring them to my eye, my eyelashes kind of brush up against the glasses, causing some dirty spots.  Now I see why people get laser eye surgery.  ;)", "timestamp": "1413828763"}, {"author": "Danni", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693328247512", "anchor": "fb-693328247512", "service": "fb", "text": "I know my glasses actually correct my vision better if I don't have them all the way up against the bridge of my nose. Changing the distance between the place where the correction is occurring (the glasses lens) and the eye itself changes the effectiveness of the correction to a slight degree. Most people who use glasses don't have severe enough visual impairment in the first place to notice the difference, but in my case, it is severe enough that if I change the position of my glasses, I can tell that I'm not getting adequate correction. So I keep them in the spot where they work best, and compensate for the field-of-view issue by using wider lenses.<br>I also have long eyelashes, so my glasses need to be far enough away from my eyes that I don't have my lashes brushing up against them. This is both because it's just really annoying to have that happen, and also because of the above reason -- my visual impairment is severe enough that even a little bit of schmutz is going to majorly affect my vision.", "timestamp": "1413829258"}, {"author": "Matt", "source_link": "https://plus.google.com/113951350991359002027", "anchor": "gp-1413829840762", "service": "gp", "text": "My eyelashes scraping against the lenses is too uncomfortable.", "timestamp": 1413829840}, {"author": "Jeff&nbsp;Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693330388222", "anchor": "fb-693330388222", "service": "fb", "text": "@Oliver: \"my glasses actually correct my vision better if I don't have them all the way up against the bridge of my nose\"<br><br>The optics of your glasses are going to designed assuming your glasses are in a certain position, but at lens creation time we can choose what the ideal position will be.", "timestamp": "1413830739"}, {"author": "Jeff&nbsp;Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693330692612", "anchor": "fb-693330692612", "service": "fb", "text": "@Dana, Perry: Maybe this is a nose shape thing?  I've been assuming all noses start narrower near the bridge and then widen out, in which case you can adjust the nose pads to keep the glasses at any distance, but if your nose instead has an area where it doesn't widen then the glasses won't stay put there.", "timestamp": "1413830908"}, {"author": "Danni", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693331156682", "anchor": "fb-693331156682", "service": "fb", "text": "Above a certain level of correction, that's actually not true. The level of correction that I need requires lenses that are only physically possible to make within a very limited parameter of shape/size. So I actually can't just choose any position I want. I have to use a position where the lenses that can be made to correct my vision can go. This affects what frames I can choose, too -- I can't just pick out any ones I want, I have to choose ones that are large enough to cover my full field of vision, sturdy enough to hold the enormous lenses I have to use, and shaped in such a way that I don't end up with peripheral distortion. <br>tl;dr: extreme myopia sucks.", "timestamp": "1413831242"}, {"author": "Amelia", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693333127732", "anchor": "fb-693333127732", "service": "fb", "text": "It's like bras; one can go her whole life wearing something that doesn't fit quite right. Why? Because, unlike Jeff, most people don't sit around wondering, \"what's my ideal boob/eyeglasses position?\" They just get used to a thing and then that's the thing they do.", "timestamp": "1413832521"}, {"author": "Jeff&nbsp;Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693333272442", "anchor": "fb-693333272442", "service": "fb", "text": "@Oliver: I see why the frames would need to be sturdy enough, and that once we've picked a lens location and level of coverage that determines a minimum lens size; what I'm not understanding is why the lenses can't be targeted for a different location.  Is it that the correction needed for myopia this extreme pushes the boundaries of what we can make a lens do?  Or that if they were going to be closer to the eye then they would need to be even thicker?<br><br>(I'm not doubting your experience, I'm trying to understand how this works.)", "timestamp": "1413832631"}, {"author": "Justin", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693334594792", "anchor": "fb-693334594792", "service": "fb", "text": "I share Oliver's long-eyelash problem. But I like to have them as close as possible (i.e. just out of lash-range).", "timestamp": "1413833409"}, {"author": "Daniel", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693334649682", "anchor": "fb-693334649682", "service": "fb", "text": "you could follow this up with a piece on how people wear their guitar straps.", "timestamp": "1413833451"}, {"author": "Jeff&nbsp;Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693335273432", "anchor": "fb-693335273432", "service": "fb", "text": "@Daniel: I don't know about guitar straps, but I do have strong opinions on mandolin straps: http://www.jefftk.com/p/mandolin-straps", "timestamp": "1413833842"}, {"author": "Dana", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693335537902", "anchor": "fb-693335537902", "service": "fb", "text": "I also second the eyelash collision remarks, and add in some eyebrow collision remarks for good measure.", "timestamp": "1413834059"}, {"author": "Vivian", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693336126722", "anchor": "fb-693336126722", "service": "fb", "text": "My peripheral vision is good enough that it doesn't benefit much from glasses-correction, and my eyeballs do not rotate enough that I can look directly at somewhere outside my glasses, so it wouldn't benefit me very much to move my glasses closer to my face.  (I chose my frames to be wide/tall enough that this is the case.)", "timestamp": "1413834423"}, {"author": "Danni", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693336376222", "anchor": "fb-693336376222", "service": "fb", "text": "Yep...it is indeed that the correction needed for myopia this extreme pushes the boundaries of what we can make a lens do.", "timestamp": "1413834536"}, {"author": "Carol", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693337139692", "anchor": "fb-693337139692", "service": "fb", "text": "My glasses work best when they are pushed all the way up, but nonetheless they slide down all the time. This pair that i have now is in a plastic frame that doesn't have any adjustable nose pieces, so that is definitely part of the problem.", "timestamp": "1413834711"}, {"author": "Carol", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693337528912", "anchor": "fb-693337528912", "service": "fb", "text": "And Jeff, I have a similar question to yours - why don't people pull their pants all the way up? I really don't care for that baggy-below the-crotch look, and it seems like it would feel terrible too.", "timestamp": "1413834847"}, {"author": "Cynthia", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693365936982", "anchor": "fb-693365936982", "service": "fb", "text": "Because all the glasses I have EVER worn cause skin breakdown that high up, Further down, they do not.", "timestamp": "1413848316"}, {"author": "David&nbsp;German", "source_link": "https://plus.google.com/111229345142780712481", "anchor": "gp-1413851137630", "service": "gp", "text": "I don't like the sense that the nose pads are nearly in my eyes.", "timestamp": 1413851137}, {"author": "Angela", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693371924982", "anchor": "fb-693371924982", "service": "fb", "text": "My glasses also do not stay up on my face.", "timestamp": "1413852305"}, {"author": "Mycroft", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693381326142", "anchor": "fb-693381326142", "service": "fb", "text": "I put them very close to that, but if I push them *all* the way up, they collect oil from my eyebrows.", "timestamp": "1413857608"}, {"author": "Cynthia", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693381994802", "anchor": "fb-693381994802", "service": "fb", "text": "I think you long eye lash folks are secretly braggin...", "timestamp": "1413857946"}, {"author": "opted out", "source_link": "#", "anchor": "unknown", "service": "unknown", "text": "this user has requested that their comments not be shown here", "timestamp": "1413858351"}, {"author": "Alex", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=693403701302", "anchor": "fb-693403701302", "service": "fb", "text": "I'm surprised no one's mentioned this yet; if I push them father up, I can feel then push on my tear ducts.", "timestamp": "1413873420"}, {"author": "Charvak", "source_link": "https://www.facebook.com/jefftk/posts/693325842332?comment_id=717351045632", "anchor": "fb-717351045632", "service": "fb", "text": "Jeff, the effective power actually increases as the lenses move closer to your eyes.  In the extreme case, they become contact lenses, whose prescription is always less strong than spectacles.  It makes sense to me to use smaller lenses placed closer to the eyes because they can be smaller.<br><br>If you do any thinking about spectacle lenses, the first thing to know is that they're not at all like camera or telescope lenses.  Those lenses are designed to use their entire surface area for viewing along a single axis.  Parabolic shapes are optimal for them.  Eyeglasses, on the other hand, use only a small circle of their area at a time as your eye moves around, so they have to be ground spherically for a start, with adjustments for complicated higher order effects.<br><br>Your lenses appear thin, so I assume you have a low prescription.  At higher prescriptions, our field of view is limited by chromatic aberration and comatic astigmatism.  Both would be solved by having highly curved lenses that wrap around such that the part of the lens you eyeball is using is always perpendicular to the direction you're looking.  Given that such high curvature would look weird, my solution is to stick with lens materials of high ABBE number to minimize chromatic aberration.", "timestamp": "1428454665"}]}