"Thị lực của bà của tôi vẫn tốt."

Translation: The eyesight of my grandmother is still good.

[Dan553966]

While "The eyesight of my grandmother is still good" is correct and grammatical, English speakers would say, "My grandmother's eyesight.... " 99 percent of the time.

[elohels]

Agreed, it's a direct translation and sounds off

[StewartMM]

"My grandmother's eyesight" is now accepted.

[Mu6OVm]

Looking at the hints, I cannot believe that "lực" means "force".