Dr Tony Holohan has urged people to wear face masks "correctly and safely" instead of visors.
The Chief Medical Officer at the Department of Health said visors do not offer the same "benefits" as face masks, which give "far better protection".
He said it was particularly important for people in retail to wear masks and not visors.
He said: “The commitment to the spirit of the public health advice shown by people across Ireland since the onset of the Covid-19 pandemic is to be commended.
"This includes wearing a face mask where social distancing is difficult, in shops and on public transport.
"However, it is also vital that they are worn correctly and safely.
"Ensure you are fully covering both your mouth and nose with the face mask.
"Remember, visors do not offer the same benefits as face masks.
"I want to particularly highlight that it is very important that those who work in settings such as retail avoid the use of visors and instead use face masks.
"Face masks offer far better protection, and they should be worn by everyone who can wear them.
"Wearing one prevents someone who does not know they have Covid-19 from spreading it to another person.
"They are a key element of our defence against this virus, alongside staying at home and avoiding meeting people outside your household."
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