tag:blogger.com,1999:blog-1556840114165332146.post5207447242193144706..comments2024-03-11T06:54:56.037-07:00Comments on Photonics for a Better World: Cataract surgery: misnomer?Anonymoushttp://www.blogger.com/profile/05206559124767437263noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-1556840114165332146.post-1486401165736458382016-05-10T11:00:37.225-07:002016-05-10T11:00:37.225-07:00Interesting blog.
Remember that people live a l...Interesting blog. <br /><br />Remember that people live a lot longer now than they once did. Presbyopia may be a fairly recent development, now that so many of us live long enough to experience it. Through history much of the detailed artwork was probably done by artists with extreme myopia. <br /><br />Even today a lot of detailed rug weaving in the third world is done by children who can see the threads without spectacles. With several Diopters of accommodation the actual specs on the eye focal length and size were always pretty loose.<br /><br />Did you choose optimum focus for distant vision or for reading? They asked my wife for her preference and she asked me for advice. I said "neither; you want hyperfocal correction, so go for 1 meter." (Prescription -1 Diopter.) Her doctor was surprised, but want along with it. They hit it for one eye and only missed by 1/4 Diopter for the other. The result has been excellent! Most of the time she does fine without glasses, but has progressives to perk up her vision at the near and far limits. She doesn't need prescription sunglasses and will be all set if she ever goes diving with a mask.<br /><br />My own cataracts are changing so slowly I may never need to have them swapped out, but I'll select hyperfocal if I ever do.<br /><br />dumpsterdiveladhttps://www.blogger.com/profile/05296636733423295606noreply@blogger.comtag:blogger.com,1999:blog-1556840114165332146.post-43261109101184545222016-04-13T09:35:43.395-07:002016-04-13T09:35:43.395-07:00I think you could say the image is consistent with...I think you could say the image is consistent with a cataract but it could also be consistent with uveitis or Exposure keratitis or other media opacity like PCO a growth on an ICL or intraocular lenses lens or glistenings in intraocular lenses<br />Can JGhttps://www.blogger.com/profile/13312744606203538816noreply@blogger.comtag:blogger.com,1999:blog-1556840114165332146.post-71146161481882401262016-04-07T11:45:01.530-07:002016-04-07T11:45:01.530-07:00Roger, sorry my ID was omitted, Scott Rowe posted ...Roger, sorry my ID was omitted, Scott Rowe posted above.Unknownhttps://www.blogger.com/profile/16654979115411503284noreply@blogger.comtag:blogger.com,1999:blog-1556840114165332146.post-25415199912909169772016-04-07T11:40:44.291-07:002016-04-07T11:40:44.291-07:00Hi Roger, thanks for sharing your thoughts and exp...Hi Roger, thanks for sharing your thoughts and experiences with this. You raise a number of interesting points. Allow me to share my thoughts from a perspective of an optical engineer immersed in ophthalmology since the 80's...The focal length of the eye (ave total optical power is ~ 58D) is a perfect optimization of field of view (>110 degrees depending on orientation) depth of field and resolution. The crystalline lens remains flexible (until we reach our 40's in most cases) to allow for good near field vision and importantly, stereopsis, without which we would not have the fine motor skills that we do. All of this does argue for intelligent design, and a Designer, but I will leave the religious implications there. On the question of the vitreous, its functions are poorly understood by most optical engineers and modelers of the eye. It is a matrix of collagen bands and hyaluronic acid that forms a very consistent optical transmission "window" throughout the visible, adds UV protection, but importantly acts as a mechanical scaffold for the eye as well as a shock absorber. It is the last line of protection for the retina, which has no real mechanical strength. Many good books on the subject, Atchison and Smiths "Optics of the Human Eye" goes into a lot of detail about the optical performance of the eye. Unknownhttps://www.blogger.com/profile/16654979115411503284noreply@blogger.comtag:blogger.com,1999:blog-1556840114165332146.post-80386719232959964972016-04-07T11:40:04.947-07:002016-04-07T11:40:04.947-07:00Hi Roger, thanks for sharing your thoughts and exp...Hi Roger, thanks for sharing your thoughts and experiences with this. You raise a number of interesting points. Allow me to share my thoughts from a perspective of an optical engineer immersed in ophthalmology since the 80's...The focal length of the eye (ave total optical power is ~ 58D) is a perfect optimization of field of view (>110 degrees depending on orientation) depth of field and resolution. The crystalline lens remains flexible (until we reach our 40's in most cases) to allow for good near field vision and importantly, stereopsis, without which we would not have the fine motor skills that we do. All of this does argue for intelligent design, and a Designer, but I will leave the religious implications there. On the question of the vitreous, its functions are poorly understood by most optical engineers and modelers of the eye. It is a matrix of collagen bands and hyaluronic acid that forms a very consistent optical transmission "window" throughout the visible, adds UV protection, but importantly acts as a mechanical scaffold for the eye as well as a shock absorber. It is the last line of protection for the retina, which has no real mechanical strength. Many good books on the subject, Atchison and Smiths "Optics of the Human Eye" goes into a lot of detail about the optical performance of the eye. Unknownhttps://www.blogger.com/profile/16654979115411503284noreply@blogger.comtag:blogger.com,1999:blog-1556840114165332146.post-29526115425397278072016-04-07T08:44:31.224-07:002016-04-07T08:44:31.224-07:00Excellent article, Roger. "Lens replacement s...Excellent article, Roger. "Lens replacement surgery" it is!Ronian Siewhttps://www.blogger.com/profile/15974394596128500332noreply@blogger.com