eTable 2. Distribution of the answers on myopia in the parent questionnaire (PQ) of the KiGGS baseline study (2003–2006) and KiGGS wave 2 (2014–2017).

		Age group
		0–2 years	3–6 years	7–10 years	11–13 years	14–17 years
KiGGS baseline survey: myopia (PQ)
Refractive error: Myopia	Do not know	466	243	235	168	209
	Yes	4	90	339	453	834
	No	2264	3376	3328	2224	2355
	Missing data	71	166	246	231	338
	Total	2805	3875	4148	3076	3736
KiGGS wave 2: myopia (PQ)
Refractive error: Myopia	Do not know	238	160	90	59	49
	Yes	7	94	276	469	879
	No	1169	2944	2788	2153	2190
	Missing data	41	239	378	345	455
	Total	1455	3437	3532	3026	3573