Just saw the post re testicular cancer and thought I would mention a similar sort of thing.

Our son is almost 8 months and has been diagnosed with retinoblastoma, childhood cancer in the eye. His tumors were detected from a photo I had out on Facebook where I had used a flash. Basically one eye correctly reflected red as you often see but the other eye reflects white or has a white glow about it. A friend saw the photo and said it wasn't normal, and within 24 hours we had a tentative cancer diagnosis.

Our ophthalmologist said they now suggest mothers take a photo of their child from birth until 5 years, using a flash, once a month and check for a double red eye reflection. You may need to remove the red eye fix on your camera to do it.

It's such a rare cancer but so easy to 'test' for, so please take the time to look at your photos and photos of friend's kids. If its detected early enough it's much easier to treat