I prefer my wearing my contact lenses to wearing glasses, and find that the glasses in fact give me sensory issues, while the contact lenses just go in and I forget about them. But that's just me -- there are people, even NT people, who cannot tolerate contact lenses, and the optometrist will usually give a little test-use to a new user to find that out.
Personally, wearing glasses creates problems for me not only because I get sensory issues about having "face furniture" touching my face and it drives me crazy after a while, but more importantly I can't seem to reconcile the different view of what I see through the corrective lenses and what my peripheral vision can see "around" the lenses, and I even lose my balance just walking. I have enormous problems with glasses.
By contrast, contact lenses are a dream, because they give a total perception of having normal vision and there's no conflict peripherally. You just see the whole world 20/20.
Sensory-wise, a correctly fitted contact lense should be so comfortable that you don't notice it in (a bit like, ahem, a correctly placed tampon!)
However there is one thing that may cause sensory issues to your son -- contacts can and do tend to feel a bit "dried out" after a long day of wearing, and they can feel uncomfortable then. But at that point it's usually beyond time to take them out, clean them, dispose, or soak overnight or whichever is called for.
I'm only at the start of getting my diagnosis, but I experience all the sensory issues of a spectrum person so I'm hoping that my answer can contribute some help.
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