ELIZABETH, Colo. -- When four-year-old Trystan Slade came home from preschool saying his eyes were "blurbly," his parents immediately scheduled an appointment with a doctor.
His parents almost canceled the appointment, after a preschool teacher told Trystan's mother Traci Slade that, "he just wanted glasses," to be like a friend.
Luckily, they changed their mind.
"We already had the appointment," his mother said. "We might as well take him. Thank God we did."
At the ophthalmologist's office, doctors soon realized something wasn't right. The blood vessels in Trystan's retina were abnormal, and he was diagnosed with an extremely rare genetic disease called Familial Exudative Viteroetinopthy or FEVR (pronounced "fever").
The disease is unpredictable, sufferers may never show any symptoms or they could go blind.
"When I think of fever, I think like everyone else: 'He has a fever?'" said Todd Slade, Trystan's father. "But then she (Traci) explained that he has a disease and that he could go blind within weeks."
In Trystan's case, doctors said he had already lost most of his vision in his left eye, and while he still had 20/20 vision in his right, he needed immediate surgery to save the sight he still had.
Dr. David Johnnson with Colorado Retina Associates said that if caught in time, FEVR can be treated with laser surgery, effectively cauterizing blood vessels to keep the disease from getting worse.
"It is very, very rare," said Dr. Johnson, who said the disease is so uncommon and likely so often undiagnosed that there are no estimates on how many people have it. "There's really no cure. Really, all we can do is try to manage the disease and preserve as much vision as possible."
Two months ago, he performed laser surgery on Trystan's eyes.
"The laser that we did looks really good. Everything is holding together," he said while examining Trystan.
Trystan will be under Dr. Johnson's watchful eyes for many years to come as he monitors the disease.
"We're going to be lifelong buddies," said Dr. Johnson. "It's going to be gratifying to help Trystan keep the vision he has."
Trystan's parents believe there is a reason for everything.
"Trystan had a guardian angel that had us go to the eye doctor that day. There's a reason that that happened," said Traci Slade.
As lucky as they feel, they said every parent wants to protect their child from hardships.
"It's tough knowing he's not going to have both eyes to see," said Todd Slade. "I'm a flight instructor. If he wants to fly together so that he can experience flight, we'll do it that way. I don't want anything to hold him back."
Doctors say children adapt quickly to the loss of vision in one eye and compensate with the other, which is likely why his parents had not realized his left eye was almost blind until a doctor told them.
"I can see out of this eye, but not this eye," said Trystan in matter-of-fact manner, right before he ran to play on the playground.
"I don't think it's going to slow Trystan down," said his father with a smile. "As you can see, he doesn't slow down much."
Trystan's parents say their decision to take their child to an eye doctor is what saved his vision. They want to spread that message, in hopes it can help other children.