An abnormally pale optic nerve is called optic atrophy. There are many causes. If all cases are considered, also all ages the most common cause is probably poor circulation (the medical name would be non-arteritic and arteritic anterior ischemic optic neuritis. This is more common in older people, smokers, diabetics, people with collagen vascular disease.
It's also important to know that some nerves look "pale" but are really normal and the white color comes from the optic nerve being stretched (as in someone highly nearsighted) or a lack of normal pigmentation around the optic nerve.
If you have been told in the past (hopefully years ago) that you optic nerve looked pale then that makes it much more likely you do not have something "new" causing the problem.
However given the fact you're having all these headaches its likely the ophthalmologist will want to get a MRI of your head. Especially as it would seem from your posting that the headaches are new and not something that's been going on since the accident in 2003.
JCH III MD Eye Physician & Surgeon
What would be the likely hood of this being a brain tumor ?? What is the most commen reason for have a "pale" optic nerve
Optic nerve pallor is a very serious symptom as many of the things that can cause it are both sight and life threatening. For example a tumor could be pression on the optic nerve, the eye may have had optic neuritis, a vascular stroke, etc.
It could be due to your car accident but you will most likely need a variety of tests to make sure that is the cause. You will need to see an ophthalmologist or neuro-ophthalmologist for an exam, have optic nerve photos, visual fields, color vision testing. You likely will need some blood work, may need to see a neurologist, likely need a MRI of the head and perhaps orbits also. And careful follow up to make sure it doesn't get worse.
You need a general physician, if you smoke you need to stop, diabetes, high blood pressure and blood disorders, high cholesterol need to be excluded and if pressent treated.
You need a summary of these tests work-ups so that in the future if you move, your insurance changes or you want to change physicians they have all the extensive work-up and it doesn't need to be repeated.
I'm also assuming that you do not smoke and are not a heavy drinker with a poor diet as that can cause problems for your optic nerve.
JCH III MD Eye Physician and Surgeon