A cracked lens or failed internal component can make a complete replacement look unavoidable. The better decision depends on the housing, internals, parts and overall condition of the assembly.
Surface treatment, lens replacement, internal repair and complete refurbishment address different parts of a headlight. A surface problem does not establish an electrical fault, and a failed DRL does not automatically condemn the original housing.
Use this overview to choose a pathway, then use the complete decision guide for the lens/housing/internal-component comparison, examples, costs and approval process. Repair suitability still requires the exact headlight and damage to be assessed.