Physical immortality dating
Telomerase is an enzyme which rebuilds the telomeres in stem cells and cancer cells, allowing them to replicate an infinite number of times.
No definitive work has yet demonstrated that telomerase can be used in human somatic cells to prevent healthy tissues from aging.
Preventative medicine is becoming better understood. Neurodegenerative diseases like Parkinson's and Alzheimer's may soon be curable with the use of stem cells.
Biological immortality is an absence of aging, specifically the absence of a sustained increase in rate of mortality as a function of chronological age.
A cell or organism that does not experience aging, or ceases to age at some point, is biologically immortal.
Genes associated with type 1 diabetes and certain types of cancer have been discovered allowing for new therapies to be developed.
Artificial devices attached directly to the nervous system may restore sight to the blind.