Regular eyesight tests could cut hundreds of road accidents, HSA and the Institute of Advanced Motorists (IAM) have said in a joint statement.
The two organisations said there were 3 million company car drivers in the UK and 17 million people traveled to work by car each day.
But millions of drivers put themselves at risk, and broke the law, because their eyesight was below the safe minimum standard, they said.
They added that this was an important message for the corporate sector.
Plus, thousands of motorists, who know they should wear glasses, drove without them, either because of vanity, or because they forgot them, or because they were only driving a short distance.
HSA and IAM have estimated that 1 in ten drivers would actually fail a driving test because of poor eyesight, if they re-took it today.
Officially drivers should be able to read a number plate from 20.5 metres (67 feet), or 25 metres (82 feet) for the new style font introduced in September 2001. This is approximately the length of two standard buses.
More than 50% of the UK population wears glasses or contact lenses and this statistic rises to 80% at age 45. The average cost of a sight test is only £15 and the average price of a pair of glasses is approximately £105 (3).
IAM chief examiner Bryan Lunn said: "Our joint message with HSA is a very serious one. It is not only very dangerous to drive if you cannot see properly but you are also breaking the law.
"The IAM strongly recommends that all drivers get their eyes checked regularly."
HSA's cash benefit schemes provide help towards the cost of everyday healthcare, including optical charges. This includes sight tests, glasses and contact lenses (plus other benefits such as dental, osteopathy, consultation, chiropody and hospital in-patient).
