A US study of more than 509,000 nursing-home residents has found that those who received at least one dose of the shingles vaccine within a year of admission had a 5.8% lower risk of developing dementia over the following four years. Published in the Annals of Internal Medicine, the observational analysis adds to a growing body of international evidence—from Wales, Australia and Canada—linking varicella-zoster virus reactivation to cognitive decline. Scientists theorise that by preventing shingles, the vaccine averts the neuroinflammation and accumulation of Alzheimer’s-linked proteins that the infection can trigger in the central nervous system.

Separately, an observational study of roughly 2,000 adults with type 2 diabetes, followed for five years in the UK, indicates that continuous use of the diabetes drug metformin is associated with a 37% slower progression of intermediate age-related macular degeneration (AMD). The results, published in BMJ Open Ophthalmology, offer a plausible biological mechanism: metformin activates the AMPK pathway, reducing oxidative stress and inflammation in the retina, a tissue with exceptionally high metabolic demand. Researchers say a randomised clinical trial is now needed to establish causality.

The findings resonate at a time when clinicians across continents warn that vision loss is too often dismissed as an inevitable part of ageing. Cataracts, which the World Health Organization estimates cause 40–45% of global blindness, are frequently mistaken for normal age-related decline, yet they are reversible with a brief surgery. In Indonesia, the endocrinology society Perkeni reports that roughly 70% of the country’s 20 million adults with diabetes remain undiagnosed, leaving them at high risk of diabetic retinopathy and other complications that can permanently impair sight. Neurosurgeons in India emphasise that visual symptoms—double vision, gradual field loss—can be the first sign of a brain tumour, underlining that the eye is not an isolated organ.

Even when diseases are identified, treatment must be carefully tailored. At the same conference in Bandung where undiagnosed diabetes was flagged, specialists stressed that LDL-cholesterol targets should be stratified according to cardiovascular-kidney-metabolic syndrome stage: for diabetic patients who have already suffered a heart attack or stroke, the goal is below 55 mg/dL, while those without complications may aim for under 100 mg/dL. In selecting diabetes drugs, physicians are urged to consider kidney function and cardiac safety, with new-generation SGLT2 inhibitors such as enavogliflozin offering an option that may also slow renal decline. South Korean firm Daewoong announced plans to build a production facility in Cikarang, West Java, potentially improving access and lowering costs.

For the broader population, the next steps are clear: researchers are advocating for prospective clinical trials to confirm the neuroprotective and retina-protective effects hinted at by current observational data. Health authorities in Indonesia and elsewhere are intensifying screening drives to catch diabetes earlier, while ophthalmologists repeat a simple message: seeing less is not a normal consequence of age, and a timely consultation can preserve both sight and—if the shingles vaccine evidence holds—cognition.