You know how to protect your eyes from the outside in: Wear shades to shield against UV rays, and cover your eyes whenever you see oncoming projectiles, be they bugs or baseballs.

Now here's how to protect them from the inside out: Get plenty of lutein, vitamin C, and glutathione. Read on for how much you need of each.

Vision Quest
Protecting your eyes from aging just got easier, thanks to these recommendations from RealAge experts Mehmet Oz, MD, and Michael Roizen, MD:

• Lutein: You can take it in supplement form at 6 to 30 milligrams daily. Or find it in corn and green leafy vegetables.
• Vitamin C: People who eat plenty of fruit and vegetables (which contain vitamin C and other bioflavonoids) are less likely to develop eye conditions.
• Glutathione: A daily 500-milligram supplement may help you avoid cataracts. Or find glutathione in eggs, garlic, avocados, asparagus, and onions.

A Clear-View Cocktail
The docs recommend this combo if you already have age-related macular degeneration: 500 milligrams of vitamin C, 400 international units of vitamin E, 15 milligrams of beta carotene, 30 milligrams of zinc, and 2 milligrams of copper -- every day, in divided doses.

Ol' Young Eyes
Here are more tips and tools for keeping your vision from clouding:

• See into Your Future -- What's normal, what's not, and how to deal with vision changes.
• Parched Peepers -- Five ways to soothe dry, irritated eyes.
• It's Okay to Cry -- Why shedding tears is good for you.
• Eye Medicines -- Eyedrops and ointments to cure what ails you.