Franklin contrasts the judgement needed before marriage with the tolerance needed afterwards. Keeping one’s eyes “wide open” means considering a prospective partner carefully before making a lasting commitment, rather than allowing affection or enthusiasm to obscure important differences, habits or problems.

Once married, however, Franklin advises keeping the eyes “half shut”. The phrase suggests overlooking minor faults rather than constantly searching for reasons to criticise a spouse. It does not mean ignoring serious harm or behaviour that requires attention. The broader lesson is that good judgement and tolerance have different roles at different stages of a relationship: caution is valuable before commitment, while patience and acceptance can help sustain it afterwards. The saying recognises that no partner is without faults and that lasting relationships often depend on distinguishing significant problems from ordinary imperfections.