Presbyopia is a global problem affecting over a billion people worldwide. The prevalence of unmanaged presbyopia is as high as 50% of those over 50 years of age in developing world populations, due to a lack of awareness and accessibility to affordable treatment, and is even as high as 34% in developed countries.
Surgical and pharmaceutical correction for presbyopia has been 5 years away for the last 20 years. Contact lens and lens implant corrections are decent but always require some sacrifice in quality.
Whoever cracks this nut should get a Nobel Prize in Medicine.