Workplace Medical Mystery:Blurry vision affects a print press operator

Posted on by Stephanie Stevens, MA


MM1At first it was only an annoyance. Jim thought it would go away.

Then it became dangerous.

Jim works at a big printing company that produces labels for consumer products. If you have a can of motor oil in your garage or a jar of hair mousse in your bathroom cabinet, chances are the label came out of his shop or from one of its three sister plants.

Fifty-two years old, Jim has worked at the plant as a press operator since it first opened almost 20 years ago. In the operation, workers load 80- to 100-pound rolls of paper or plastic onto eight massive rotary presses. Colorful water-based and fluorescent inks are kept in several five-gallon pails around each press. As needed, ink is pumped into troughs where the presses’ printing cylinders with their flexible rubber plates are mounted. The sheets of paper or plastic run through the cylinder, the rubber plates apply the ink at high speed, and bright labels emerge. The process is called flexography printing.

As a press operator, Jim is responsible for running the printing presses, which includes filling the pails with inks and additives as needed, inspecting printed labels for defects, and trouble shooting.

Jim had noticed on and off that his vision seemed blurry after a days’ work, but lately it had been happening more frequently. Now that Daylight Savings Time had ended, Jim was finding it hard to see as he drove home in the dark after his shift. The glare from oncoming headlights was almost blinding. “Could I be developing a cataract?” thought Jim—after all, his father had cataracts. At the urging of his wife, Jim scheduled a doctor’s appointment.

Over his lunch hour, Jim met with the doctor and described to her how he felt like he was looking through a fog by the end of day. The doctor proceeded to have Jim read the eye chart. She noted that he wasn’t able to read the last row of letters. She also observed that his cornea appeared cloudy.

She listened to Jim’s concern about cataracts but reassured him that even though his symptoms were consistent with cataracts, because his vision problems seemed to resolve by the next day a cataract was unlikely the cause of his vision problems.

Jim’s doctor also considered an abnormal swelling of the cornea known as corneal edema. Corneal edema is most commonly diagnosed in people 50 or older, like Jim. Patients typically complain of blurred vision or seeing “halos” just as Jim had. After a closer examination with a special microscope, the doctor saw some signs of swelling. The doctor prescribed eye drops to help reduce the swelling and ease the symptoms Jim was experiencing.

A few weeks went by and Jim’s vision was still blurred; the eye drops weren’t helping.

What could be causing Jim’s symptoms? Share your ideas in the comment section below and check back on Friday for the next installment.


This is the first installment in the NIOSH  Workplace Medical Mystery Series. The name and certain personal details of this character are fictitious and do not represent an actual person or persons.


Stephanie Stevens, MA is a Health Communication Specialist in the NIOSH Office of the Director.



Posted on by Stephanie Stevens, MA

27 comments on “Workplace Medical Mystery:Blurry vision affects a print press operator”

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    In as much the claim is that the ink used at the print press is water-based we still need to check the chemicals and the exposure to vapour from these chemicals could be responsible for Jim’s corneal edema and swellings. We need to also check with other workers using or working closes with these chemicals – full risk assessment is indicated. Jim needs immediate job change or rotation away from the presses and these chemicals for a few months and then re-examined.

    I suspect Jim is suffering from extended exposure to VOCs that offgas from the inks he uses in the printing process.

    The following comes from MSDS for fluorecent paint:

    Eyes: Causes eye irritation. Prolonged or repeated exposure may be harmful to health. May cause conjunctivitis, irritation,
    and inflammation of mucous membranes. May cause burning sensation, redness and tearing (watering). Possible
    severe irritation. Contains materials corrosive or severely irritating to the eyes. Temporary vision impairment (cloudy
    or blurred vision) is possible. Severe irritation, tissue damage, and possible blindness will result from direct contact.

    Check worksite for engineering controls, proper ventilation, break times away from chemicals etc.. Also ask if he is supposed to/does wear PPE and ensure he is doing so correctly. Check with management if there has been recent changes in chemicals or handling to prevent reoccurence.
    This is fun!

    I used to work in a foundry where they used tertiary amines as catalysts in curing isocyanate resins. The tertiary amines caused corneal edoema which cause blurry vision (halo vision when looking at lights).

    RE: ” Is he wearing proper eye protection?”
    Eye protection is designed to protect from projectiles and splatter and does not provide any protection from gases or vapors. Dimethylisopropanolamine (DMIPA) or dimethylaminoethanol (DMAE) could be responsible. Workplace air monitoring is indicated.

    A consultant industrial hygienist must conduct a workplace evaluation. It appears that an IH from NIOSH is already doing so. First: what are the chemicals vapors that he is exposed to? What are the solvents of the inks used in this process? Is he exposed to air contaminants above the published occupational exposure standards? If so, what improvements to industrial ventilation are needed. Will respiratory protection be required until engineering controls are installed? Ensure employees are getting site-specific Hazard communication training.

    A review of CHEMINFO and HSDB databases for key words “blurred vision” and “ink” or “inks” comes up with a list of chemical suspects that I would focus on when I looked at the material safety data sheets for the printing inks.

    Over exposure to these chemicals is suspect and a sampling strategy would be developed based on presence on the MSDS and olfactory confirmation of odour(s) in the workplace.

    4-(1,1-dimethylpropyl) phenol
    ethylene glycol

    My suggestion for the cause of Jim’s symptoms isn’t chemical but physical due to “painting” or coating of the cornea with a very fine mist of inks generated by the high-speed flexible rubber plate printing process.

    The MSDS had some useful data. Work practices should also be observed to see if Jim touches his face or eye areas after handling chemicals and recently printed labels.

    If Jim worked there for 20 years without issue, then something has likely changed.

    It could be Jim’s body’s ability to recover from exposures or the exposure has changed…and/or the offending source has significant potential for bio-accumulation and chronic manifestation – which seems less likely.

    I would be interested in evaluating if formulations, work practices or controls have changed to narrow in on possible sources. Formaldyhyde seems to be showing up in a lot of materials and specifically attacks the optic nerve and could also cause local irritation. UV light is also used for curing of some water-based inks (not mentioned), but UV exposures could be associated with has there been recent exposure to the UV curing lamps?

    Further, since this is a “workplace mystery” everyone assumes it is work-based. In the real world, I would be asking about changes outside of work as well…it could be Jim is using pesticides at home which organophospates or carbamates,

    Proper eye protection can not be achieved through goggles or faces shields unless he is exposed to a mist, which is unlikely. The airborne concentration of a VOC in the goggle will approximate that outside the goggle, since they leak and do not have filters. If PPE is required, a full-facepiece respirator with appropriate filtration will be required. Obviously, more effective ventilation would be the first and most important step.

    Looking at chemical make up of inks, solvents, and maintenance products used along with possible changes in engineering controls would be my starting point; and agree with Kerri W.; This is fun.

    Look for changes in the work area: chemicals, machine degradation due to age (releasing more vapor?), HVAC changes. Are gloves needed (hands touching face/eyes), and are the paper rolls emitting small particulate? Amines are odiferous; any odors present? Is good hand washing being done before breaks? UV exposure causing cloudiness would not get better overnight. Check out the roller cleaning process. solvent is probably being used.

    I think it’s the hands carrying chemical to the eyes.

    I agree with others who have already mentioned this. I am studying isocyanates and came across a document at that mentions “exposure to high levels of amines have been reported to cause visual disturbances, including blurriness. cloudy vision and halo vision, symptoms that usually resolve after being away form the exposure for a day” These are the similar symptoms being described by worker possibly form his occupational exposure.


    I been working for 8 months in a food packaging factory in Canada, Toronto, where they use press machines, pouches, theres also an extruder(ink and solvents are used with all the machines) a laminator where they use some kind of glue that some people at work are saying it causes cancer if you touch it to tape the raw material or something I’m not so sure but I have the same problem Jim is talking about, my eyes go red and burn a lot and whenever I leave work I can’t see vision is blurry and sometimes I can’t even drive my car because my eyes become very sensitive to light. I want to quit my job because of it. I never experienced this ever in my life. I would say Jim is definitely have this because of the place where he works. I’m 32 by the way and this is just not right. they never even told me anything about any of this when i started working for them. places like these should be inspected regularly for the employees safety.

    We are sorry to hear about your health issues. If your vision problems continue you should see a health professional. If you haven’t yet read the blog that solves the mystery, you can find it here

    In this case, the blurred vision was a result of amines, chemical compounds typically used as solvents, in the ink and ink additive. Additionally, workers add pH adjuster to the pails of ink every day that also contained a similar amine. In this case, when the pH adjuster was diluted with water and the ink pails were covered to reduce the amount of chemicals that evaporated into the air, workers no longer reported vision problems.

    You might want to share this blog with your employer. Since you are in Canada, you can contact the Canadian Centre for Occupational Health and Safety to get help with a workplace safety and health issue:

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Page last updated: December 7, 2016