The wearers choose to purchase prescription glasses online. Although they could buy some discount glasses, that maybe based on sacrificing quality for quantity. Especially for those prescription glasses, which the bifocal and progressive eyeglasses are more complicated.
Sometimes, experts study found that the bad lenses caused by the below cases:
(1) Watching object is ambiguous – issues caused by the top power of lenses (SPH) are too low
(2) Feeling sick – the reason is that the SPH is too high
(3) Getting the double image – there might have the slight aberration in CYL or AXIS power
What causes the problem of progressive or bifocal lenses?
Linear Mode
