Red eye in iPhone

In iOS10:

• Open the Photos app;
• Select on the photo you want to fix redeye on;
• In the upper right hand corner tap on Edit;
• Select on redeye correction tool — it looks like an eye with a line through it;
• Tap on each red eye in order to correct it;
• Select Done.

Note: you won't see the redeye correction tool unless you are trying to edit a photo that actually contains a redeye issue. iOS10 auto-detects redeye issues and only offers the tool when there's something it thinks needs to be corrected.