can you cure daltonism??

Answer 1

No, it's genetically determined.

There are a few tricks which can help people distinguish colours that they find difficult:
for example, when viewed through a red filter, two "identical" pencils will show their difference as the green one goes "black".

This has been developed into the use of one coloured contact lens (x-chrom and other brands) where a "lustre" effect helps with colour discrimination in some cases.
It does not provide "normal" colour vision.