On Sunday 03 July 2011 13:21:31 Robert Heller wrote: > > Actually, now that I think more and more about it, I am not so sure it is > > not doable. However, it is far from being trivial, and it certainly > > cannot be something that can be as thin as ordinary shades. It has to be > > bulky and heavy (due to the optics inside) and is bound to impair your > > vision of the real world. > > > > If I get some free time, I might even try to calculate the properties of > > such a system of lenses, but I'm skeptic that the cool "monitor-shades" > > will ever be possible. ;-) > > OTOH, I would expect that people in the 1890's would consider the Apollo > Moon landings as 'impossible'... So, given enough advances in optics and > monitor techology: LCD screens that can switch to complete > transparency or to varying levels of transparency, and things like > programmable lenses / optical systems, it becomes concievable. Well, sure, but you have to make a very fine distinction between prejudices and facts, when it comes to making these sorts of predictions. I remember to have read somewhere that in 18th century it was widely believed that the human body cannot withstand velocities greater than 60 km/h, for whatever reason. But this was just due to the people's ignorance of the difference between velocity and acceleration. But when it comes to making claims about the optical properties of the human eye, no prejudices are involved --- it has been well explored and studied, and limits of what the eye can see (without artificial help) are a matter of fact, rather than unsupported opinion. ;-) There is *no* *way* to have a plain eye read anything at 2 cm distance --- this is a fact, easily verifiable if you put your palm in front of your eye. Now, with some clever lenses and optics you might be able to trick the eye into thinking that the object is at a greater distance, and therefore circumvent this limitation. But having these optics constrained onto a width of typical shades is an *extreme* stretch, ultimately bounded by laws of physics. The laws of physics that apply here are already known, well-studied laws of geometric optics, and have to be obeyed regardless of any technological ingenuity. I haven't done any serious research, but I can say offhand that they provide very very little space for any hi-tech manouvers, no matter how advanced. The more likely approach to what you want is to have some apparatus that dynamically measures the current width of the eye lens, and use a super- tightly focused laser to draw the monitor picture directly on the eye retina. AFAIK, that is concievable, *provided* you can create a laser beam thin enough not to disperse drastically going through the eye lens, and thin enough to provide good "monitor resolution", and make it in appropriate color(s), and have low-enough power not to damage the retina on continuous exposure. By dynamically measuring the eye refraction properties, the device could in principle adjust the laser drawing to accomodate to the current position and the focus of the eye itself. The end result would be a person seeing glowing text "written" on the object that the eyes are currently looking at. When you look at something else, the device adjusts and you see the text written over a new object. *If* you are technologically advanced enough to create a laser beam with such properties, this kind of a thing would be doable. Note, though, that the requrements of the beam being thin enough and low-enough in power may be in conflict with each other, and not satisfiable simultaneously (to be honest, I'm not sure without some digging into it, but at the very end you cannot circumvent Heisenberg's uncertainty principle, if all else can be done). But if that can be done, I can imagine a device like that to be constructed somehow. Nevertheless, even then, this device would look like two lasers pointed into your eyes, and certainly *not* like cool shades. ;-) Best, :-) Marko