Hello, Brian - I know there have been a lot of comments on contact
lenses, and especially given your recent note, I’d like to add two
more - one about the glasses, one about handling
chemicals…
Contacts are not the problem. But Airborne contaminants of any kind
*can damage contact lenses, or get under them, or in some cases cause
the lens to adhere to the lens.(see Re: DEET below) Any of these pose
a risk to your eyes, and your eyesight. It’s one thing I personally
would not risk under any circumstances, the story below will tell 'ya
why I feel that way,. Especially if close up work is your passion. I
think it VERY important that your eyes with or without contact lenses
be protected from the sides as well as the front when doing any work
that might create airborne contaminates. I’m not referring to
projectiles, but more smaller particulate matter.
Then there is the Serious importance of hand washing - Re: DEET -
Well I TRY not to use it, but this strong insect repellent is the
best there is for repelling black flies, and we do have clouds of
them in the spring here in New England. If you have ever been
"attacked" by the critters, you know why people resort to DEET,
despite it’s toxicity. They leave you bloodied and itchy and they are
aggressive as all get-out.
About 10 years ago, on a mountain climbing trip in Baxter State
Park, Maine, I made the error of scheduling the trip during the height
of black fly season. I realized the error the first day on the trail,
and promptly coated myself with DEET - this included my face. With
many 1000’s in a swarm, and DEET boasting 95% efficacy, I still had
hundreds of bites. 
DEET makes it clear that not only should it not
stay on your skin for more than 6-8 hours, but that it an melt
synthetics - such as your nylon windbreaker, car seat fabric, etc. But
no mention of contact lenses. The problem was, that on the trail,
water to wash hands is in short supply. So, an itchy bite here, a
rearranging of a bandana/hat there, a sweaty brow wiped here, and it
was on my hands. I washed my hands a few times in a stream, and from
my canteen, but there was still residue under my nails. Then it
happened, the old “something in my eye”. (it was flies, ick) Just a
light touch, and apparently the DEET on my hands melted the lens to
my eye, which I did not discover until a day later when I tried to
remove them. It was painful and a nightmare. Luckily no permanent
damage, but the moral is - if you are handling ANYthing chemical,
WASH YOUR HANDS very thoroughly before touching eyes. A nailbrush is
a good idea. And if you can protect the lenses from everything with
side protective glasses, then it’s more than a good idea. I know
goggles can be a real pain, and even a hindrance to vision - but
think of the risks and the resulting problems… So in my
opinion there are decidedly some risk when wearing lenses that are
not present if not wearing them
But Just my opinion… :o) Sincerely, Mary Beth M.O. In Rural
New Hampshire, USA where it’s so cold even the icicles are
shivering! (-35 F at night all this week)