1 Iritis is uncommon, but can be due to trauma, infections, or autoimmune conditions. Symptoms include pain, red eye, and often, decreased vision.  Optic neuritis. The nerve travelling from the back of the eyeball into the brain can become inflamed.
Oak root fungus, or white rot, is a widespread disease that becomes visible just beneath the bark and on roots. What looks like layers of light brown to tan mushrooms form in clusters at the base of the trees.
Fungus gnats look like tiny, black flies with grayish transparent wings. The adults are about 1/16-in (.2 cm) long and have long legs and antennae. Being so small, they can enter a home through the tiniest of openings.