About: Tom Mangan is a veteran freelance writer with more than 20 years of newspaper journalism experience. Though most of Mangan's clients are in the B2B technology sector these days, he brings a wealth of personal insight to All About Vision.

A congenital birth defect gave Mangan low vision in one eye and poor eye protection in the other. The low-vision eye has a rare defect called a coloboma that provides a field of vision but does not allow sharp visual focus.

The other eye has conventional nearsightedness but still has issues thanks to a facial-nerve defect. The eyelids on this eye do not close fully, causing dryness and sensitivity to bright lights.

None of this slows Mangan down. He enjoys eight-mile hikes in the mountains of North Carolina, always wearing his sunglasses with polarized, polycarbonate lenses for extra eye protection.

Mangan’s low-vision eye prevents him from seeing 3-D effects in movies, video games and TV shows. He is eternally grateful.

All About Vision articles by Tom Mangan

Wayfarer sunglasses history: From WWII to Hollywood to now

Men’s eyeglasses: Tips to find the perfect pair

Aviator sunglasses: How do you wear them?

The ultimate Ray-Ban Wayfarer guide

How should your Aviator sunglasses fit?

Fake Wayfarer sunglasses: How to spot them

How to find durable men’s eyeglasses