儿童视力下降往往与户外活动不足和用眼时间过长有关。Értóng shìlì xiàjiàng wǎngwǎng yǔ hùwài huódòng bùzú hé yòngyǎn shíjiān guò cháng yǒuguān.A decline in children's eyesight is often related to insufficient outdoor activity and excessive time using their eyes.
她视力不好,看黑板得戴眼镜。Tā shìlì bù hǎo, kàn hēibǎn děi dài yǎnjìng.Her eyesight is poor, so she has to wear glasses to see the blackboard.
医生让我检查一下视力,看看要不要换眼镜。Yīshēng ràng wǒ jiǎnchá yíxià shìlì, kànkan yào bu yào huàn yǎnjìng.The doctor had me get my eyesight checked to see whether I need new glasses.