A deficiency in vitamin B12 leads to many health issues and one of those issues is damage to the nervous system including damage to the optic nerve. B12 deficiency disrupts the nervous signal traveling from the eye to the brain causing a condition known as optic neuropathy. Symptoms include blurred or disturbed vision.
People that are most prone to vitamin B12 deficiency are those who are vegans or vegetarians because B12 occurs naturally in animals and not vegetables. Foods that are naturally high in B12 are: beef liver, fish, chicken and dairy products.
Optic neuropathy due to vitamin B12 deficiency is usually reversible simply by supplementing with vitamin B12 tablets. Once the B12 levels have risen to normal range, the tablets can be stopped. In rare instances, supplementation will need to be continued for life.