Child can not recognize, or associate the alphabet?

Needing a little help. I have a child who can not associate, or recognize the letters of the alphabet at all. I have done several methods of assessing the child, but so far things have failed. We have been working for some time and the child’s parents have been working since 2 years old. The child is school age now.
Any ideas, advice? Any suggestions?
However, even numbers are too difficult to recognize. However, the child can recite the alphabet and count to 100 but as far reading or seeing the alphabet or numbers is to hard. And the child does wear glasses, and they are new.

Has the child been tested for dyslexia? I think this is one of the signs.

If the child just got glasses he may not have been able to see all the material that was previously shown to him. You may need to start at the beginning, assuming that he can now see with his new glasses.

What does he do when he is asked? Does he look at the card and guess wrong, look away from the card and guess wrong, or just not guess at all. If he does guess, is he close? If he really could not see well enough before, and parents have been working with him since he was 2, he may have developed emotional issues associated with learning during that time period.

The child looks away and guesses. The child isn’t no where near right. The child is recieving newer glasses then the new ones soon. So maybe that will help. The child has been tested for dylexia and the tester could not tell due to the issue with the child’s eyes are so bad. I’m concerned that it could possibly be something serious.