I keep getting denied disability for blindness, because of lack of medical evidence. What options do I have?

I originally filled for disability in June of 2008 and was denied due to me not meeting their current requirements for Blindness. I went ahead and appealed the matter which was again denied due to lack of medical evidence. As of May 2009 I reapplied for disability due to me having multiple diagnoses on top of the blindness. I was denied again due to my condition not being severe enough because of age, education, training and work experience. I went on to appeal this claim and was denied the reconsideration due to them stating that my condition was still not severe enough. I have been seeing an ongoing neurologist and M.S doctor for treatment for the past 2 years and as of May, 2010 I will be starting treatment for Multiple Sclerosis per my doctors recommendations due to other possibilities being ruled out.

What can I do at this point?