Regular soft contact lens wearers' comprehension of graphical symbols labelled on multipurpose solutions

Symbols are commonly used to represent information of health care products included multipurpose solutions (MPSs) for contact lens (CL) care.

Little knowledge is available about recognition and comprehension by regular soft CL wearers of commonly used symbols in the instructions of CL MPSs marketed worldwide.

CL wearers from the UK and Spain were invited to answer an anonymous on-line questionnaire (distributed though Facebook and Twitter) concerning the recognition and comprehension of seven common symbols (ISO 15223:2017 and EN 980:2008) included in MPS package instructions.

Answers of one hundred-ten soft CL wearers who use MPS (27 in the UK and 83 in Spain) were analysed showing low recognition and comprehension of the surveyed symbols even in wearers with > 5 years of CL wear (71.8%). The CE marked was the most recognised (96% in the UK and 88% in Spain, P = 0.29) and understood (78% in the UK and 85% in Spain, P = 0.25) symbol, but other important symbols, such as 'Caution' and 'Do not reuse', were under recognised (22% in the UK and 19% in Spain, P = 0.78 and 11% in the UK and 6% in Spain, P = 0.40 respectively) and understood (close to 30% in both countries P > 0.15). Participants with > 5 years of experience, showed slightly higher comprehension (P < 0.05) in some symbols ('Sterilised'; 'Do not reuse'; 'Use by date' and 'CE marked').

These results suggest an insufficient comprehension of seven common symbols included in MPS instructions among regular CL wearers in the UK and Spain without high impact of CL wear experience. Improving the education and symbol comprehension of regular CL wearers could help to get better patients' behaviour and safe use of MPS in soft CLs care.