In 2A Questionnaire 2, adult Lifelines participants filled in questionnaire about eye conditions, developed by the Department of Ophthalmology at the UMCG (section: diseases & symptoms).
The questionnaire contained both general questions and questions from validated ophthalmological instruments:

• VISION1-5: general questions on the use of vision aids
• VISION6-24: questions derived from the VFQ-25 on visual impairments and related functional limitations
• VISION25A/B: general questions about the diagnosis of macular degeneration and glaucoma
• VISION26-28: questions derived from the Short Questionnaire for Dry Eye Syndrome (SQ-DES)
• VISION29-30: general questions about (laser) eye surgery
• VISION31A1-5: general questions about the use of eye drops or gel

Note that Lifelines also assessed eye conditions with various general questions.

The Visual Functioning Questionnaire (VFQ-25) is a vision-specific measure of health-related quality of life, composed of eight multi-item scales, four single-item scales, and one composite score ranging in value from 0 (poor) to 100 (high). The full VFQ-25 consists of 3 parts:

1. overall health and vision
2. functional limitations due to vision
3. dealing with problems due to vision

In Lifelines only part 1 and 2 of the translated VFQ-25¹⁾ was used. Thus far, there is no information available regarding validity and reliability of this subset.
For the full VFQ-25, Mangione et al. (1998)²⁾³⁾ was the first to show that it is reliable and valid. They showed that the psychometric properties of the NEI-VFQ were not influenced by the type or severity of the underlying eye disease, suggesting that the measure will provide reproducible and valid data when used across multiple eye conditions.
The VFQ-25 has additionally been shown to be valid and reliable in several populations and eye diseases ^4)5)6)7)8)9)

(Dry Eye Syndrome (DES/DED or Keratoconjunctivitis sicca) is the condition of having dry eyes. Other associated symptoms include irritation, redness, discharge, and easily fatigued eyes. Blurred vision may also occur. The symptoms can range from mild and occasional to severe and continuous. Scarring of the cornea may occur in some cases without treatment.
There are no validated Dutch dry eye questionnaires. The SQ-DES, derived from the Women's Health Questionnaire, is a short and simple questionnaire of three questions leading to a dichotomous outcome (DES or no DES) and is unequivocal to translate. Other questionnaires (like the Ocular Surface Disease Index (OSDI) or Ocular Comfort Index (OCI)) have been shown to be ‘random number generators’ on a population level and include too many questions to be included in Lifelines (more than 10 each).
The English SQ-DES has been validated by Gulati et al. (2006)¹⁰⁾ as a sensitive and repeatable tool that is easy to administer in large epidemiological studies.

• Bazeer, S. et al (2019). The relationship between occupation and dry eye. The Ocular Surface 17(3); 484-490
• Vehof J. et al. (2020). Prevalence and risk factors of dry eye in 79,866 participants of the population-based Lifelines cohort study in the Netherlands. The Ocular Surface: in press
• Neustaeter, A. et al. (2020). Glaucoma in large-scale population-based epidemiology: a questionnaire-based proxy. Eye (Lond): in press