How long does it take for scratched cornea to heal?

Typically, 24 hours: The cornea turns over new cells every 24 hours, so typically a scratch will heal withing 24-48 hours, depending on how deep the scratch may be. You also need to be concerned that there is still not a foreign body present in the eye or the eye becomes infected. If your vision is affected, the pain increases, symptoms not improving, the eye is getting more red or is matted in the am, see your doc.

Dr Villaplana and another doctor agreed

2-7 days: Depending on the severity this will usually take between one day and one week.