Aims: The aim of the authors' study was to determine the prevalence of myopia and premyopia in children and adolescents attending primary school in a village in the north of Slovakia in the period before and after the peak of the Covid-19 pandemic. Material and methods: Changes in the spherical equivalent and axial length of the eyes were measured in 2019 and 2022 in a group of 47 children and adolescents within the age range of 7–12 years at the time of first measurement. In all the individuals, refraction was measured using an automatic keratorefractometer without the use of cycloplegic eye drops, and axial length was measured with an optical biometer. Refraction was also measured using an automatic keratorefractometer after using cycloplegic eye drops. Results: We recorded a significant change in the mean spherical equivalent (1.02 ±1.16 D vs. 0.72 ±1.29) and the axial length of the eyes (23.05 ±0.72mm vs. 23.30 ±0.74mm) when comparing the measurements from 2019 to 2022. The probands manifested a myopic refractive shift of -0.30 D throughout the entire cohort (-0.24 D in boys and -0.38 D in girls), and the mean axial length increased by 0.2 mm in the entire cohort (by 0.3 mm in boys and 0.2 mm in girls). The percentage of myopic and premyopic eyes increased (4.3% vs. 8.5% a 31.9% vs. 48.9%). Conclusion: We noted a decrease in the spherical equivalent and increase in the axial length of the eyes after the Covid-19 pandemic compared to the period before the pandemic in Slovak school-aged children. During this period, the prevalence of myopia and premyopia increased.