Flyglasses

I want to be able to generate a mosaic or 'pixellated' effect in real time, using only optical processes (i.e. no electronics).
Ideally, in a thin and small enough sheet to be able to look through it like spectacles.
It turns out you can purchase small lenses which 'pixellate' light, but these unfortunately have a viewing distance of 20cm, which is too far for spectacles.

So here's the strategy I've come up with. The sheet is divided up into 'tiles'.
For the process to succeed, we want to average the light incident on each tile across the whole tile.

The strategy I propose is to first focus the light (which we can assume is effectively parallel) to a point, randomise the light direction and then re-parallelise the light using a second lens.
In practice, this uses a lensing sheet (an array of small lenses), a frosted layer and a second lensing sheet.