Nobody said smoking weed caused anyone's blindness.
Smoking "dope" did through. I would assume that is speed or something. He refers to it as some sort of chemical.
I'm am seriously misunderstood around here about as much as a hallucinogen is. Now I know how they feel. lol
I figure since dad used to do some sort of dopey chemicals and went blind, but now he only smokes weed and drinks beer, why not see if he'll go for some DMT and tell me what he sees.
You appear to be misunderstood due to your lack of explanation. This is a global forum, 'dope' can be assumed to be many things, typically in the UK it is for either Weed or Heroin. Be more clear next time.

And upon that note, I find it highly unlikely that either of those drugs caused blindness so it may be worth finding out more about the actual condition before suggesting DMT, but I don't wish to cause offence so don't consider it fact.
Even so, what I'm trying to explain is if someone believes that a drug has caused their blindness, surely that thought is something that lurks at the back of their mind when consuming drugs? Anxiety, even if minor, before a psychedelic trip for someone even experienced is common. Especially something like DMT, which as I'm sure you know initially feels like your head is blasting off to hyperspace. For many, that sort've feeling can be frightening at first and this is people with sight and awareness for something that is going on. I know that if I was in your dads position and I felt that initial 'click' and rush of the DMT in my brain and believed drugs caused my blindness I would go into panic. Thoughts that are irking at the back of the mind are known to reappear and influence trips as well so please consider this. I suggested mushrooms because they are much more mellow and easier to handle, they also last longer so much more can be gained from the experience - it will also still provide a rough answer to what you are interested in but more so for psychedelics as a whole rather than DMT and like I said there is nothing stopping you working your Dad up to DMT and that way the experience is likely to be much more rewarding and he will be able to give much better analysis/response to your questions afterwards as he will already be aware of similar effects due to mushrooms.
I know many people who have taken DMT once who aren't too experienced with drugs, they aren't able to tell you much about the experience apart from it was intense, scary at times. When I ask them to describe they are unable to, I'd expect a similar experience with a blind person - although I could be wrong! I'm only stating these things so that if you do end up doing it you can take as much as possible from it - after all it is fairly uncharted territory in articles.
Excuse me if this sounds harsh, but your Dad is not a lab rat, and feeding him extremely powerful psychedelic drugs is not a DIY lab experiment. I think you need to give some serious thought as to why you're doing this and what you would like to accomplish. At the very least, if you are going to do this, spend some time explaining to him exactly what's going to happen. The important thing isn't maintaining the integrity of your "experiment" by not telling him too much; the important thing is your Dad.
Although you've already explained this, I do have to say I agree with folding_space. From your post it appears your more so interested in initiating someone into DMT and seeing their reaction, mainly because they are your dad and blind. While it is a good experiment, you really need to think it through. You can only assume you wish to give your dad DMT by making a thread like this, otherwise could you not have just used the title 'Effects of DMT on a Blind Person'.
My input here does nothing for any of you.
You guys say I am the one who is far out?
How can you guys say that to me when it's obvious most of you are just skimming through what I wrote and adding input based on what you think you saw.
Stop overreacting, look at the start of my post to possibly understand why.
Hope this makes things more clearer, but it appears you don't really have any interest in it. But this sort've information is good for introducing anyone to psychedelics in my opinion.