You know how they always tell pregnant women not to change the litter box? This is why.
I had a patient in today that contracted toxoplasmosis as a child or possibly an infant. The first picture is of the relatively "normal" right eye. The round, white thing is the optic nerve head. The black, patchy things are toxoplasmosis lesions. The dark area to the left of the optic nerve is the macula... the area where the light coming into your eye focuses and is responsible for your central vision.
The left eye wasn't so lucky. The enormous lesion encompasses the entire macula, essentially causing a blind spot in the central vision. The toxoplasmosis lesion has eaten entirely through the retina. All of the retinal tissue is gone and the bright white area is the reflection of the inside of the white of the patient's eye.