Poor blood flow to your optic nerve is the most common cause of optic nerve damage.
Optic nerve damage is often referred to as ischemic optic neuropathy.
Other causes of optic nerve damage include glaucoma, optic neuritis, trauma, infections, diabetes, toxic substances and optic nerve head drusen.
Bacterial infections which include Lyme disease, syphilis, cat scratch fever and other viruses such as measles, mumps and herpes can also cause optic neuritis.
Glaucoma causes elevated pressure within the eye and can damage the optic nerve and lead to vision loss.
Optic neuritis which is inflammation of the optic nerve can be caused by various things including autoimmune diseases such as multiple sclerosis or lupus and infections or even post viral infections.
Injuries to the eye or head can also lead to optic nerve damage.
And tumors can compress your optic nerve and cause damage.
Some infections such as measles and syphilis can also damage your optic nerve.
Diabetic retinopathy which is a complication of diabetes can cause optic nerve damage.
Exposure to some certain chemicals and toxic substances can also damage your optic nerve.
And Optic nerve head drusen which is deposits of protein and calcium salts can form on your optic nerve head and restrict blood flow and potentially restrict the blood flow and potentially cause optic nerve damage.