I beg to differ. "Sight words" do not build a proper foundation for understanding new words. They also hinder development of speed reading or even just proficiently fast reading.
(I know that last bit sounds counter-intuitive because speed readers read entire words or even sentences at once. However, I am one, and a good foundation regarding how words are formed from letters is critical to developing speed reading skills.)
JMHO, of course.
My son was reading before he went to kindergarten. They tried to teach him to read with phonics. Didn't work because he already knew how to read.
If you want your child to read, and read well, before he/she starts school here is what needs to be done.
Read to your child every night before bedtime. There are books available that have stories for every day of the year.
If you do that, I guarantee that your child will be reading to you before he/she starts school.
I and my wife did that, and it works. Plus, an unbreakable bond is developed between you and your child.