Table 1.

Observational association between time spent in education and refractive error

Exposure	Outcome	Model A*				Model B†
		No of participants	Effect size	P value		No of participants	Effect size	P value
Time spent in education‡	Refractive error§	69 798	−0.178 (−0.185 to −0.170) (dioptres/y)	<2e-16		37 734	−0.165 (−0.179 to −0.154) (dioptres/y)	<2e-16
Refractive error§	Time spent in education‡	69 798	−0.154 (−0.161 to −0.147) (y/dioptre)	<2e-16		37 734	−0.136 (−0.145 to −0.128) (y/dioptre)	<2e-16

^*Included sex and age as covariates.

^†Included age, sex, Townsend deprivation index, birth weight, whether breast fed, and northing and easting coordinates.

^‡Age full time education was completed (in years).

^§Average measured mean spherical equivalent refractive error (in dioptres).