Blurred or Distorted Vision

Has anyone looked at a way to simulate blurred or distorted vision in their games? I can imagine lots of fun use cases, especially in horror environs.  Character Specific Examples: A near-sighted wizard can only see "clearly" for 10 ft., but everything beyond this range is blurry. (A far-sighted Ranger could be equally fun). Glasses or Goggles that grant a special power, while distorting everything you see. Everything on the map is blurry for a poisoned character. Environment Examples: Certain objects are seen by all characters as distorted (themselves in a hall of mirrors, or objects behind an evil haze). While I understand you could just make a distorted map, what I'm talking about here is one that looks different at various lines of sight, changing depending on character position like you experience with dynamic lighting angle changes and such. Shapeshifting environments or NPCs I suppose some of these things would need to be hooked into the dynamic lighting tools on the back-end or the token light/sight features. But maybe some effects could be achieved using the FX tools. I am mostly brainstorming here and would be curious to hear anyone's ideas.

The only thing the API could do is put some sort of transparent image across the top that would make it hard to see what was underneath: The problem is, that would be visible to everyone.  You could setup something very complicated with the Twins script and duplicate maps, but it would be hard to manage.  FX tools have the same limitation of everyone seeing the effects, as well as not actually being able to blue things, just obscure them.

The obscure-overlay is a pretty good way to achieve environment affects. It does make me wonder what sorts of advances would be worth adding to the token sight features, or to find new ways to capitalize on dynamic lighting--which already adds so much to our games. In my examples, the use cases are limited but pretty cool.

To really do a blur or obscured vision overlay, the VTT would need to either do some fancy pixel manipulation over some area or use a WebGL shader to do some refraction techniques.

I actually have a PC that is blind and sees via echo location and Tremorsense. I have dynamic lighting turned on and set his field of vision really small. He'll do Perception checks and taps the ground loudly to increase his fov. I manually change the fov temporarily to show him what he can see, and then revert it, so having a some kind of script that changes vision would be quite helpful!

Well, you could do that adjustment with TokenMod. Or if you wanted to have a command the player can issue that also sets the vision back after a time, PM me...