The goal of this clinical trial is to determine the efficacy of valproate as an adjunct therapy to treat amblyopia beyond the critical period in children aged 8-17 years who have amblyopia of 3 lines of interocular best-corrected (with glasses) visual acuity difference.
The main questions it aims to answer are:
* Does valproate enable clinically meaningful and durable visual recovery from amblyopia?
* Do valproate-treated patients show a change in amblyopic eye visual acuity (lines)? Participants will undergo daily patching for 2 hours (standard of care) plus the addition of valproate or placebo for a total of 16 weeks.