The sub-sheet(used for the areaclose to) is a circular double-light lens,i.e.a dome double-light.

The size of the sub-sheet is 2/ 3circular,and the upper edge of the sub-sheet is a straight-edged double-light sheet,i.e.a flat-top double-light sheet.

The shape of the sub-sheet is not so obvious,and the appearance of the sub-sheet is closer to that of the double-light sheet of the ordinary lens,i.e.the invisible double-light sheet.

In order to solve the problems of blurring and jumping objects in the middle distance of double-light lenses,Shanghai Conant Optics invented three-light lenses,that is,an intermediate light zone was added between the far and near-sighted areas.It provides a powerful guarantee for the visual health of the middle-aged and elderly patients with optometry.

Patients with high hyperopia or aphakia have very high diopter,and the lenses needed are usually very thick and heavy,which greatly affects the correction.
Conant hats adopt the principle of reducing the diameter of lenses,which can reduce the thickness and weight of lenses as much as possible under the premise of guaranteeing the diopter.  
The preferred product for patients with high hyperopia.
Frequent assembly and wearing effect.

Comparisons of common lens and hat lens