The warning comes from HSF Health Plan, which found 48% of surveyed workers said they were putting off going to the dentist or opticians after seeing costs rise by up to 30% in the last two years.
HSF director Stephen Duff said: "The cost of living is going up everywhere, but as more and more put off visits to the dentist or optician, there will be an increase in preventable diseases such as mouth cancer and glaucoma."
In July the Commons Health Committee found that nearly one million fewer people are seeing an NHS dentist since 2006.
According to the HSF Health Plan report, 70% of respondents believed dental visits should be paid for out of taxation, while 57% said government should pay for optical bills.
Rising health costs put staff at risk
Cash-strapped workers are risking their health because they cannot afford the rising price of medical check-ups.