The 20-20-20 rule
To reduce eye strain and fatigue, follow the 20-20-20 rule: every 20 minutes, take a 20-second break and look at something 20 feet away.
Para reducir la fatiga visual, sigue la regla 20-20-20: cada 20 minutos, descansa 20 segundos y mira algo a 20 pies de distancia.
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