Fast pupil dilatation and slow pupil dilatation have the following differences 1, the drugs used are different 2, the time of action is different The former is an hour after the time of action, 8 hours after the pupil back to normal, while the latter is 3 days to reach the time of action 20 days after the pupil back to normal. 3. The size of the effect is different. The former is not complete, while the latter is more complete. Since eye regulation is inhibited after pupil dilatation, it is important that children be less exposed to bright light, participate in less confrontational sports and games, and read less during pupil dilatation. It is recommended that if your child needs glasses, use a slow dilatation, otherwise a fast dilatation is sufficient.