A black eye generally lasts about 1 to 2 weeks, with most bruising and swelling improving significantly within this time frame. However, complete healing can take up to 2 to 3 weeks depending on the severity of the injury. The bruise usually changes color over the healing period, starting dark purple or blue, then fading to green or yellow before disappearing. If a black eye lasts longer than three weeks or is accompanied by severe symptoms, medical attention should be sought.