Wow...by the time he's big enough to reach all the keys ( and assuming he keeps his 'voice' when it break ) he'll have one hell of a singing voice...really talented young lad.

He needs a taller stool, that's half his problem.

@2 that wouldn't work
his foot wouldn't then reach the pedals
Know yo instruments

#3. I doubt if he's using the pedals.
Know yo' kids.

#3 You are a plonker Mrs Fried chicken, as Foxy said kids often don't use peddles at that age, he needs to be raised up so his arms and hands are in the correct position to reach the keyboard, then irrespective of sight issues he wouldn't be missing so many notes. His current position is going to greatly affect his position muscle memory as he grows and make it more difficult to progress. Perhaps this isn't the actual piano he usually plays, but if it is and he wants to use the pedals, his parents should fix some pedal extenders for him https://youtu.be/PXb5qep844M but get him a higher stool!!

Keep in mind two things:

1 - He is six years old
2 - His sight is impaired

And some personal references, I know that even with my 25 years of experience I would have struggled to make that song blindfold in a month. To the downvoters, I dare you to give us a video where you do exactly that at April 30th!

Well done kid and the very best

Mad respect. Keep playing little buddy.

https://www.youtube.com/channel/UCEFFl4jVhSQLx-r-08kYtng/videos