The Korean round glasses fashion has been around for a couple of years. However, before you jump into this fashion trend, be aware that, from a mechanical perspective, this frame is "designed" to slip down your nose. That's right. Myopia corrective lens are thin in the centre and gets thicker towards the edges. With a big round lens fitted into one of these frames, you are maximising the weight of the lens. Heavy lens are the main reason that drags your glasses down your nose. Although the opticians will try their best to adjust the grip better, it is not always possible to counter the force of gravity. There are a few ways that you may try to mitigate this.
For a start, a high index lens may help. These lenses are thinner so it is likely to be lighter. However, depending on the model, high index lens material may be heavier so the reduction in thickness may or may not contribute to significant reduction in weight.
Taking reference from your ears, choose a frame that is lighter at the front of your ear but heavier behind your ears. The weight of the frame from the portion behind your ears will act as counterweights to the front portion carrying the lens. While this is usually hard to find and the counterbalancing force is not strong, at least don't choose one that is heavy at the front and light at the back.
If after all the selection and adjustment, the glasses still slips down your nose with annoying frequency, you may turn to accessories to hold your glasses better. The least obvious accessory is probably Friction Sleeve. This is a high friction elastomeric tube that enhances the grip of your glasses temple by friction. Should this fails, the next options will be temple earhooks. These are more obvious but they provide a mechanical anchorage to the back of your ears. Most designs in the market will significantly increase the holding ability of your glasses to stop slippage. Unlike other temple earhooks in the market, FOCUS and Flex Discreet temple earhooks are designed to be comfortable which comes from its material selection and mechanics consideration. For ladies, just let your hair down and the earhooks will be well hidden. For guys, Flex Discreet is recommended as it is designed to tuck in behind your ears.