She had plastic bifocals hanging on a chain over her heavy chest .
她沉重的胸前面挂着一架塑料的双光眼镜。
Nowadays , this type of glasses is known as bifocals .
现如今，这种眼镜被称为双光眼镜。
Nowadays , these glasses are known as bifocals .
如今，这些眼镜被称作双光眼镜。
Once the trufocal lenses are adjusted , the entire field of vision is in focus , unlike bifocals and progressive lenses , which keep only a limited area in sharp focus .
It is a condition that causes vision to progressively blur with age , causing eye fatigue , poor night vision and reliance on bifocals & reading glasses .
