Vision loss related to TBI

My son fell on the top of his head, on the left side just behind his hairline, a year and 3 months ago and sustained a concussion.  He was 8 years old. Initially he lost visual acuity in both of his eyes.  His right eye is fine now but his left one never came back to 20/20, only 20/40 plus a few letters on the 30 line. He was diagnosed with post concussive syndrome because he had ongoing symptoms like photophobia, nausea, fatigue, etc.  These symptoms have diminished now and the neurologist and I assumed he was fine. When he had a sight test last week he lost more visual acuity in his left eye. Glasses don't fix the eye sight problem. I've read that the left front part of the brain is responsible for sight but I haven't found any information on vision loss after a concussion.  Can you explain what is happening in his brain or give me a reference so that I can find out more information about vision loss after a TBI?

[TW2008]

In regards to brainmapping, Dr. Andrew Yellen has a neuro-elecrical lab which utilizes a system called the DESA (Digital Electro-Encephalogram Spectral Analysis). This is a brain mapping system complete with evoked potentials. The hardware and software was developed at Harvard and the equipment is FDA certified. There are only half a dozen or so of these systems in the country. The neurologist, Dr. Thomas Schweller does the analysis and you will know the extent of his damage and how it is affecting his auditory and visual cognition. You can find additional information at:
http://www.DESA.us

Then you can use that 'Brain Map' for neurotherapy to retrain the areas of the brain highlighted by the DESA analysis.

If you have any further questions, let me know.