Shinhmar · Scientific reports 2021 · pre-post interventional study · n=?

Weeklong improved colour contrasts sensitivity after single 670 nm exposures associated with enhanced mitochondrial function.

Level 4 - case-series / case-control

Interventional pre-post study without reported randomization or sham control group in the abstract

PubMed 34819619 · doi:10.1038/s41598-021-02311-1 · record verified 2026-08-26

What was done

Participants aged 37 to 70 years received a single 3-minute exposure to low-energy 670 nm light delivered at specific times of day. Investigators assessed cone-mediated colour contrast detection thresholds over the subsequent week to evaluate functional visual changes attributed to mitochondrial photobiomodulation.

What was found

The abstract reports that a single 3-minute exposure significantly improved cone-mediated colour contrast sensitivity for 1 week to levels comparable to younger individuals, provided the light was delivered at specific times. Specific sample sizes, baseline and post-treatment numerical thresholds, variance, and p-values were not reported in the abstract.

Why it matters

If validated, brief low-energy red-light exposures could offer a simple, non-invasive method to temporarily enhance color contrast vision in aging populations experiencing mitochondrial decline.

Limits

The abstract provides no sample size (n), no control or sham comparison details, and no numerical data or effect sizes. Visual improvements were only assessed up to one week, and the specific timing requirements for light delivery are not detailed in the abstract text.