Try not to worry. It's hard and especially since you have an older child diagnosed with autism and the disability of being blind. That must be hard! I have a boy with sensory integration disorder which many autistic kids have. when little and even now, he wants to touch on HIS terms. He wasn't super cuddly but would hug and love on me in his own way. To this day, he wants to instigate the hugs or slaps on the back from friends, etc. and he works on eye contact (we tell him to look at someone's forehead or right behind them to help him seem to be making eye contact). He has some social skills challenges and other things too. but, good news here . . . he's 13 and a successful kid now for the most part. Good grades, plays sports, has friends, etc. As he matures, he is better about eye contact as he sees that it is important. He has a friend with ADHD who still will not make eye contact. So, some people just have a hard time with it.
the bigger question is if your son is making his developmental milestones.
He may turn out to have some sensory issues or something along those lines. But I would not look for that as of yet. When he is about 2, consider a one day half day program and begin observing how it goes for him. And go from there. (unless he is not meeting milestones). I really think preschool helps you assess your kids because the teachers observe your child compared to the other kids and your child is outside their own safe environment so more things come out.
Keep in touch and let me know how it is going.