How does color blindness occur?

Hi,

Welcome to icliniq.com.

Yes, there are other causes in which color vision could get affected other than congenital or birth causes. Optic nerve damage manifest with abnormal color vision. There may me optic neuritis (inflammation of optic nerve most commonly related to multiple sclerosis), optic atrophy due to toxic (methanol) or nutritional deficiencies. Optic nerve could be damaged after trauma. Some drugs like Ethambutol (for tuberculosis), Amiodarone (used for hypertension) and many other drugs could also damage the optic nerve and can cause loss of color vision. Some diseases that run in families like cone dystrophies can also result in loss of color vision that is not present at birth, but manifests at the second or third decade of life. All these causes are almost irreversible, except if it is due to some drug. Only further damage can be stopped by avoiding the drugs. So, if anybody is having a color vision defect he needs to get a complete eye examination to rule out all the possible causes.