If you wear large-size eyeglasses often, your vision would be worse; the main factors are PD, materials of the frame
The large-size glasses is much broader than usual myopia glasses, which means the optical center between the glasses would therefore becomes broad. A myopia glasses wearer whose PD is shorter would cause the focus error of the optical center between the pupils and glasses. That means it could easily cause the eye fatigue and blurred vision. So long-time wearing would make your vision become worse.
The original lens of large-size glasses is plastic, the main function of which is to maintain the shape of the frame. If you watch things through a plastic lens, the clearness would be severely affected and in order to see clearly, the eyeballs would increase the burden of ciliary muscle. If the condition continues for a long time, the eye fatigue would be caused and the vision would become worse.
The curvature of optical center and edge varies according to the myopia glasses. There is a strict requirement on ophthalmology: the optical center of myopia glasses must correspond with the optical center of eyeballs. The large-size glasses would slip from the nose easily for it is much heavier than normal myopia eyeglass frames, which would cause the focus deviation from the optical center of the lens pupil. Once the power changes, the things you see would become blurred. If this condition continues, the vision would become worse.
Provisions of Ophthalmology:
1. The error between the pupils and the optical center should be limited into 2mm;
2. The higher the ametropic degree is, the less the error between the pupils and the optical center is.