Clear sight without glasses? - Film at 11

An ingenious invention is said to give persons with vision defects clear sight without eyeglasses, contact lenses, or eye surgery. It is a sordid tale, with users of expensive cameras tricked into seeing things that don't really exist, a major camera manufacturer intentionally mislabeling lenses, and shameful abuse of technical terminology. For the latest on this breaking story, we take you to our own Doug Kerr, who appears to the naked eye to be in Dallas, Texas.

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Well, Asher said he thought I should make the introductions to my articles more enticing, so there you are.

Now to the science.

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Many camera viewfinders are equipped with a lever or knob that controls "adjustable vision correction", primarily to allow users who are nearsighted or farsighted to obtain a sharp view of the viewfinder image without their eyeglasses.

I have just posted to my technical information site, The Pumpkin, a new technical article, "Vision Correction in Camera Viewfinders", available here:

http://doug.kerr.home.att.net/pumpkin/index.htm#VisionCorrection

It describes some optical principles involved in camera viewfinders, the nature of major human vision defects, and the principle of their correction. It then describes what the vision correction feature of camera viewfinders does and how. In the process, it explains what a diopter is, and isn't.

It also describes some special considerations in interpreting the designation of Canon supplemental vision correction lenses.

oh if it only worked

I used the viewfinder adjustments and found them useless. You can't back away from the camera and look at the scene to be shot (if you are nearsighted) without putting glasses on. So when I started with photography, I waited a while and had Lasik. Had a bad result (but still 100% correctable) but now I can see clearly with contacts in the distance and I need reading glasses to work the camera. It still doesn't help you adjust and read the small screen LCD on top of the camera to check white bal/iso etc.

So when will Canon make something useful to do this? A big sheet of glass that is a bifocal for those of us who need to adjust cameras and see small items far, far from the lens? How would it hook to the camera?

Kathy Rappaport said:

So when will Canon make something useful to do this? A big sheet of glass that is a bifocal for those of us who need to adjust cameras and see small items far, far from the lens? How would it hook to the camera?

Click to expand...

Theroeticly it could be done. However the camera would need a very high plus power lens that is thick in the middle to focus the LCDs like a hand held magnifying lens would. The focal point of teh lens would be the distance from its camera side (of the lens) to the plane of the LCD. If it is at the exact focal point the light leaving the lens toward your eye would be parallel and therefore focused at infinity. If it is infinity light you could see it with your distance glasses, contacts, or naked eye if you don't need corrrection. Problem is that the closer the lens is to the camera the thicker and heavier the lens would have to be. This makes it impractical to attach to the camera.

So, bifocal lenses with the camera held at 10-16 inches built into your own glasses is still the most practical.

Now, if a "heads up" style display using a projected virtual image out is space were used it would work. This may be a feature of the camera of the future!

It's a strangely disorientating experience to have the only clear view of the world around you to be through the camera's eye. I've tried it for a while and gave it up as an amusing trick.

And Kathy. Yikes! I guess I'll give it a few more years before I try lasik.

older and wiser

When I had my last eye exam, the MD said that if I only wore one contact, I would have a monovision effect. Well, on my trip to Istanbul and beyond, I packed all left eye lenses - I wear daily disposable lenses. So that meant either glasses or one eye corrected via contacts. My dominent eye is the left and I had those contacts, so I tried it. I can't read a book that way, but, for my photography - it's perfect! No reading glasses to read the camera windows and distance vision is good for photography. Took a day or two to get used to - but, a great solution for me.

Definitely, I would do lasik again - I would ask to have my vision checked multiple times and I would NOT do it in a teaching hospital. I would only do it with a doctor with a lot of experience in a private practice. Also, I would have a complete physical before hand to make sure that you don't have any vascular, cardiac or problems with fluid retention.

Hi guys for almost 10 years I suffered Astigmatism and it’s been a killer to me esp. for the things that I do everyday. And earlier as I was surfing over the net about Lasik thing I saw an important information about how to determine if you’re a Lasik candidate or not and since im planning to undergo Lasik sooner or later this year I want to share this information to you all because I know that it can be helpful to some people who also have the same concern like mine. Anyway, there are three questions you can ask yourself before moving forward first, are you over 18? Second, have you had stable vision for the past year? And third, is your goal to see clearly without glasses or contacts? I took this information from my2020. Hope it helps you in a little way.

We actually got a lot from this post.

1. The reminder that eyes are complex and we shouldn't take perfect sight for granted. However, I'm one for minimizing surgery. Wearing glasses is a simple solution for most of us.

2. The knowledge that moderators are alert to spammers. Thanks Cem!

3. Following from this I was able to get rid of a bunch of others in my group to check. So this saved considerable time.

We do get rid of of thousands of people this way! A smaller community with just photographers is way better than massive poor quality growth.

Asher