Interesting.

I've been trying to describe my visual field defects to people I know and for the most part I've settled on "It's a big ring of fuzzy bullshit around the center of my vision" and then I make wiggly waggly hand gestures in front of my face. Not precise like a lattice, but seems to work.

There's acuity/blurriness, but also spottiness, center vision only, peripheral vision only, color blindness, and then vision that varies throughout the day and night (sometimes inconsistently). Nystagmus, alternating and non-alternating strabismus, etc. Egad, how many variables does one want to define?

There's a free app called Tengo Baja Vision (I Have Low Vision) that gets around the problem of explaining low vision by simulating a number of common vision conditions. Here's the English language link:

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And though this answer shoots off on a bit of a tangent (cough, geometry joke), I hope it's semi-relevant. Describing vision is one thing; being able to demonstrate a very rough approximation can save a lot of words, and a lot of math.