Can a magnifying mirror or prism be used somehow as a low-tech reading aid for the visually impaired?

[David_Bee]

The magnifying glass is widely used as a low-tech assistive device for reading by the visually impaired. As magnifying power increases, the lens diameter must decrease, greatly constraining the field of view. But a magnifying mirror achieves high magnification over a broader field of view, and is widely used as an assistive device for grooming. Lateral inversion (and obstructed view) interfere with using the magnifying mirror for reading. Seeing as such problem are overcome in periscopes and reflecting telescopes, might some solution (eg. multiple mirrors, prisms) make a magnifying mirror or prism useful for reading?

 

[David_Bee]

As someone who is visually impaired, I say "no". And to be honest, I am a little offended by the suggestion that you know better than me what I need. Being blind does not make me stupid.

Lordy.

Why don't you spend a couple of days trying to read everything thriugh a non-magnifying mirror and see how that works out for you.

Thanks for the feedback. Apologies. I meant no offense. I don't know better, hence my question. A member of my family is dealing with the challenges of low vision and we were tinkering around together with a magnifying mirror. That's what led to my question.

It's intended as a technical question (or thought experiment) and might have other applications besides for use as a low vision reading aid.

 

[Drakkith]

And to be honest, I am a little offended by the suggestion that you know better than me what I need.

Then I suggest you stop being offended by innocent people asking questions.

The magnifying glass is widely used as a low-tech assistive device for reading by the visually impaired. As magnifying power increases, the lens diameter must decrease, greatly constraining the field of view. But a magnifying mirror achieves high magnification over a broader field of view, and is widely used as an assistive device for grooming. Lateral inversion (and obstructed view) interfere with using the magnifying mirror for reading. Seeing as such problem are overcome in periscopes and reflecting telescopes, might some solution (eg. multiple mirrors, prisms) make a magnifying mirror or prism useful for reading?

The problem with multiple mirrors or other optical devices is size and ease of use. A magnifying lens, such as in reading glasses or a magnifying glass, is relatively small and lightweight and can be easily worn or held by an individual. Especially the elderly, who are the primary ones who need them. A device using multiple optical components quickly becomes heavy, unwieldy, and mostly unusable by the average person who would need such a device except in very specific circumstances. Also, we already have those desk mounted magnifying devices that many people use for hobbies involving very small components or detail, such as assembling and painting models of ships, planes, sci-fi space warriors, etc. Those are probably about as large and bulky as you can get and still be useful. Anything beyond that would solve little.

 

[berkeman]

As magnifying power increases, the lens diameter must decrease,

No, not if the increase in weight of a larger lens is tolerable.

But a magnifying mirror achieves high magnification over a broader field of view

Can you give some links to the reflecting magnifiers you are referring to? Thanks.

There are some pretty helpful technologies to help folks with vision issues. One of the best is a scanner/camera device that can display an enlarged image on a laptop or tablet. Maybe try a Google search similar to this:

 

[Vanadium 50]

I use a cell phone's camera and screen. Weighs less than and works better than a magnifying glass.

But we're going down the same wrong path. The starting point should be asking the intended recipient what they want, what they are doing now and what would make it work better, and what their constraints really are.

I very much doubt the answer is a large not-very-portable complex optical system that requires alignment every time it is moved.

 

[Tom.G]

Try looking for a Page Magnifier. Some of the larger office supply stores carry them, and of course Amazon has many.

Most are a Fresnel Lens made of clear, semi-flexible, plastic arount 1/16 to 1/8 inch thick. Readily available in various sizes from credit-card to book to 8.5x11in. Larger sizes are sold as a lense for a homemade "Solar Furnace".

Some come with a stand and some are intended to lay on the page.

Cheers,
Tom

 

[sophiecentaur]

But a magnifying mirror achieves high magnification over a broader field of view, and is widely used as an assistive device for grooming.

That is probably the only application where the object is an a place where a reflected image iseasily accessible to an eye. A grooming mirror has to be a suitable size with a suitable focal length to allow it to be held in the hand because object and image lay on the prime axis.

I couldn't be certain but I don't think there is a possible arrangement for 'offset' viewing at a usable distance. A book (or any other object) needs to be reachable so could you fit any mirrors / prisms in such a confined space.

I have spent some time collimating a reflecting telescope (900mm focal length) and I have found that you can get massive magnification but the image position is very unstable. A high quality eyepiece lens works very well as a 'magnifying glass' and is very easy on the eye - but it's very much monocular.

They've been making viewing aids for many many years and I reckon the mirror version must have been tried many times and it has never taken off. Maybe worth a private try / play but not much hope, I think.

 

[sophiecentaur]

I use a cell phone's camera and screen.

A great idea and you can use it over a wide range of viewing angles. The smart phone strikes again!!

 

[jedishrfu]

Years ago, I met an undergrad fellow physics major who was visually impaired. He used a small handheld telescope to view the blackboard. It worked for him in this instance, but not so much when using lab equipment.

One time in the lab, he accidentally ran a high-voltage probe back into an oscilloscope port for small voltages and blew out the scope with a loud bang. He had trouble reading the small print labels on the scope.

One factor to consider when deciding on assistive technology is the recipient's age and ability to navigate a cellphone screen effectively.

We had an elderly friend with Parkinson's who we thought would benefit from an iPad. However, we didn't anticipate the difficulty that he would have in simply selecting things from the various menus due to his constant shaking. He graciously declined the gift and passed away a few months later.

Later, I learned that someone had invented a spoon for Parkinson's that effectively neutralized the shaking by counter-shaking. I thought if only we could have found a stylus that could do that.

 

[sophiecentaur]

I thought if only we could have found a stylus that could do that.

That function could be achieved by internal software in the position decoding.

 

[sophiecentaur]

The starting point should be asking the intended recipient what they want,

I'm sure that's true in your particular case; you are a Scientist / Engineer / Gadget inventor / PF Member and you think 'that way'. However, many people need to be presented with a choice of solutions before they can make use of new technology. There is also the problem than many forms of disability reduce the ability of a user to invent stuff and produce it on their own.
But I do appreciate the "Does he take sugar" problem.

 

[jedishrfu]

That function could be achieved by internal software in the position decoding.

That feature may be there, but it wasn't when we got the iPad for him. Our friend was a hermit priest who supervised a retreat center in Texas for many years. He helped many people with his kind advice and patience. But we couldn't help him in his time of need, which made us very sad.

His Parkinson's was too advanced that he could barely see the iPad or hold it, and the shaking didn't help. Sometimes, no solution can help.