80% reduction if just wear glasses (Chinese - worn for Myopia)
78% reduction if just wear face shield
85% reduction if just wear mask
Joint probability Calculation: Wear Glasses +Wear Mask = 97%
Face Shield in ConsumerLab Sept 2020
Face shield can also provide some protection for the eyes. A review of studies of coronavirus transmission found that the use of eye protection (face shields, visors or goggles) found that the use of eye protection was associated with 78% less infection than with no eye protection, with the researchers noting that "Eye protection is typically underconsidered and can be effective in community settings." (Chu, Lancet 2020).
In fact, even eyeglasses may provide some protection: A study of COVID-19 patients in a hospital in China found that only 16 of 276 patients (or 5.8%) wore glasses (i.e., at least 8 hours per day for near-sightedness) compared to an estimated 31.5% of the general population, suggesting that wearers of eyeglasses may be less susceptible to COVID-19. The eyes are considered an important channel for SARS-CoV-2 to enter the body (Zeng, JAMA Opthal 2020).
- Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis – Lancet June 2020  PDF in VitaminDWiki
- Association of Daily Wear of Eyeglasses With Susceptibility to Coronavirus Disease 2019 Infection
- JAMA Sept 16, 2020  PDF in VitaminDWiki
- Does Wearing Glasses Protect You From Coronavirus? NYT Sept 16
- It may be that eyeglasses act as a partial barrier, protecting eyes from the splatter of a cough or sneeze.
- Another explanation for the finding could be that people who wear glasses are less likely to rub their eyes with contaminated hands.