28 Aug Signs of Autism By Dr. Tanya In Infants (4 to 12 months), Medical Information, Toddler (1-3 years) Autism is a developmental disorder that can be very complex. Signs can appear in early infancy but usually noticeable around 18 months to 2 years of age. Doctors screen for Autism, but parents should be aware of signs as well. Lack of eye Read More Share: