The measurement of eye symptoms: A pilot study

Epidemiological studies have shown that eye irritation is one of the most common symptoms reported in the indoor environment. Different terminology for eye symptomatology has been used in the literature: e.g. dry eyes, strained eyes, sore eyes, itching eyes, irritated eyes, burning eyes, tired eyes, and red eyes. A pilot questionnaire study among office workers was performed to study the dimension of eye related symptoms. Six items concerning different aspects of eye irritation were included in a questionnaire study of ergonomics among 85 employees in ten different office buildings. The six items were: 'dryness', 'itching and/or irritated eyes', 'burning eyes', 'tiredness', 'painful eyes' and 'double vision or blurred vision'. Structual equation modelling together with more traditional test of internal reliability with Cronbach alpha was performed. The items 'dryness', 'itching and/or irritated eyes' and 'tiredness' were found to be measurements of the same construct of eye irritation (Cronbach alpha=0.85). A thorough validation of the different constructs of eye symptoms is needed to study eye symptomatology and its causes in the indoor environment.