According to TV Over Mind, Kodi Lee was diagnosed with a congenital disorder when he was born, known as optic nerve hypoplasia (ONH). As the National Organization for Rare Disorders writes, this condition is "characterized by underdevelopment (hypoplasia) of the optic nerves ... Vision can range from no light perception to good functional vision, or even full vision in one eye."

Those with ONH can also have "brain malformations and pituitary problems," including in the corpus callousum which is the nerve fibers that connect the two hemispheres of the brain, underdeveloped nerve fibres, and cortical heteroptera which is an "abnormal migration of neurons to the surface of the brain."

For Lee, this condition almost resulted in his death when he was just five days old. Thankfully he survived, but the disorder resulted in Lee becoming legally blind, per Mashable SE Asia. Five years later, Lee was also diagnosed with autism. These conditions have also affected the way his brain processes his emotions, meaning that "he may spontaneously laugh, but he does not have the ability to let someone know if he is in danger or hurting," TV Over Mind reported.