On July 31, the former contestant wrote on his Instagram page, "Glaucoma at age 21, how unfortunate news this is. I just hope that I don't go blind." Kim Yong Jin had also written, "The world looks blurry and my head hurts. That's strange."  

SEE ALSO: J-Hope takes #1 with 'MONA LISA' + Stellar performance on April 17th's 'M! Countdown'!

Upon hearing this, fans sent out words of encouragement in addition to questions concerning his health.

Glaucoma is an eye condition which the pressure of the eye increases due to optic nerve damage. Symptoms include blurry vision, nausea, headaches, and even vision loss. Treatments include eye drops, medication, and surgery. The condition usually can be seen in elderly people, but symptoms in younger people are increasing. The exact cause is still unknown.

We wish Kim Yong Jin a speedy recovery.