Brains and Vision

There is a very characteristic association between a particular type of brain tumor and a particular type of vision loss.

There are brain tumors that can form at the “bottom” of the brain in the pituitary gland area. When these grow, they push on the neurons of the optic nerves as they travel back to other parts of the brain. In that area, the fibers of the two optic nerves are crossing, and the compression leads to loss of far side vision on BOTH sides. The central vision is mostly preserved, but the side vision is lost bilaterally.

Sometimes, we can find this kind of vision loss in patients that prompts us to look in the brain with an MRI. That can be how these tumors are found!