Cataracts

With aging, the crystalline lens normally takes on a yellowish color that filters blue light. Apparently there is evidence suggesting that blue-wavelength light may damage the retina by contributing to the development of free radicals in the retina

You can read about it at this site that also discuses a cure.

http://www.aao.org/aao/news/eyenet/cataract/cataract_nov_2003.htm

As we age, our natural lenses become cloudy and take on a yellow hue. Consequently, our view of the world becomes "yellow" as though we were viewing it through a yellow filter. It happens so slowly that we aren't aware of it. If you have a lens implant in one eye, however, you will be able to cover one eye at a time and notice the difference in colors.  

Its a feature of the change in the nature of the lens as the cataract develops

The lens filters out certain colors due to changes brought on by the cataracts themselves.