Be more specific when you say, "Blink a few times."

A new study published in Optometry and Vision Science showed that forced blinking can substantially affect the assessment of tear film surface quality.

Tell me about the study.

Thirty-three volunteers were assessed considering two different types of blinks: natural (short) and forced (unnaturally prolonged). Objective noninvasive breakup time estimation was performed using the Oculus Keratograph 5M (Oculus) and the E300 corneal topographer (Medmont), both equipped with tear film analysis modules, followed by the fluorescein test.

What did they find?

Forced blink significantly shortened the tear breakup time (TBUT) in all measuring modalities. The most notable difference in TBUT between natural and forced blinks was 3.2 seconds as measured with the Oculus Keratograph 5M.

The take home:

According to the authors, forced blinks affect the assessment of tear film stability, leading to inaccurate TBUT assessment. Therefore, attention should be given in instructing patients before TBUT evaluation.


How can I prevent cataract formation?

Caffeine might help.

A small study published in Acta Ophthalmologica examined 17 patients undergoing bilateral cataract surgery to determine whether caffeine in human lens epithelial cells (LECs) inhibits ultraviolet radiation‐induced apoptosis in vitro.

Tell me about the study.

Patients scheduled for bilateral cataract surgery were asked to abstain from caffeine for 2 weeks, starting 1 week before surgery of the first eye. The second eye was scheduled 1 week after the first eye, and on the day of the second eye surgery, patients were given coffee containing 180 mg caffeine shortly before surgery. Lens capsules including LECs, harvested after capsulorhexis, were transferred to a cell culture dish and immediately exposed to close-to-threshold ultraviolet radiation (UVR). At 24 hours after UVR exposure, apoptotic LECs were analyzed.

Why analyze apoptotic death of human LECs?

Because previous studies have shown that apoptotic death of LECs precedes the appearance of cortical opacities.

What did they find?

Acute oral caffeine consumption significantly decreased UVR‐induced apoptosis in LECs. This supports other epidemiological findings that caffeine delays the onset of cataract.


Asymptomatic COVID-positive nurses get the OK to continue working and treating COVID-positive patients. (via)

How long do I need to quarantine after a COVID exposure?

It depends, but the science is evolving.

Have you seen this eyewear line made from recycled ocean plastic?

Meet See2Sea. More about their story here.

See you next week!