眼力下降英语怎么说

眼力下降的英文是"decline in visual acuity"。
"Visual acuity" 是指人眼对物体的清晰度，因此"decline in visual acuity"就是指眼力下降。
一些例句：
His visual acuity has declined since he turned 40.
他40岁后眼力下降了。
The decline in her visual acuity made it difficult for her to read small print.
她眼力下降了，看小字困难。
The decline in visual acuity can be caused by a variety of factors, including aging and diseases like diabetes.
眼力下降可能由多种因素引起，包括衰老和糖尿病等疾病。