yellow-eye syndrome 

"A very rare disease that can be caught by having a strong, special bond with that person. The chances of it are 0.07%. Symptoms include:

-Clingyness

-Possessiveness

-Constant worry about them

-Sleeplessness

-Obsessiveness

-Overprotective and violent

-Jealous more often

Once their eyes turn yellow, it's a sign they have fully caught the disease. They will stop at nothing for their loved one. The cure? To distance them from the loved one for a long, long time.”