Helps for issues of adaptation

New glasses
The amount of light that enters your new lens (light transmittance) will be a lot higher than your old ones. So you may feel that they are a lot brighter to look through. It usually takes several days to get used to new glasses.

New Prescription
Some customers may feel the prescription is strong and it can almost feel a bit painful. This is normal with new prescriptions! Usually, it takes about one week to adapt to a new prescription. If after a week or even a few days, it’s still not working, you could ask your eye doctor to recheck your prescription to ensure it is accurate. You can also use your old prescription if you feel more comfortable with that.

Issues caused by the change of frame shape.
Such as changing from square to round, or from small to big. In larger frames, your lens will also be thicker. Some customers may feel a little dizzy and just like with the prescription change, it will take about a week to get used to a different frame shape and size. If you still feel dizzy, you could change to the frame style and shape you were wearing before.

Issues caused by the discordance of the prescription and lens index.
If you have a strong prescription and choose a low index lens, the lens will be thick and the blind zone will be larger, which leads to more distortion in vision. For low prescription, choosing a high index lens will reduce the light transmittance and increase chromatic aberration, which leads to a decrease in visual clarity. To clarify, if you have a high prescription, it is important to choose a thinner lens and if you have a smaller prescription, there is no need to choose a thinner lens.

Issues caused by the spherical lens.
Generally speaking, the spherical lens is thick and the image through the lens will be distorted. While, with the same prescription and index, the aspherical lens is thinner, lighter and more comfortable for wearers. The aspherical lens has a wide vision and the image through the lens is more real and natural. Wearers will not feel tired after wearing an aspherical lens for a long time.

Issues caused by glare.
Anti-reflective is a very important part of your prescription glasses. If you don’t choose anti-reflective coating, you may feel the lens is too reflective and has a lot of glare. The lens is great for pictures as the reflection doesn't show. It is also cosmetic because people can see your eyes through your lenses. So be sure to choose the coating when you order your glasses.

Issues caused by adjustable nose pads.
The position and direction of adjustable nose pads will affect the distance between your eyes and the lenses. For those who are near-sighted (those who have trouble seeing far away), if the distance is too small, you may feel the prescription is strong and you'll experience some pain in the eyes. You could try to adjust the nose pads by forcing them to stay closer and inward to each other, which will enlarge the distance. On the other hand, if the distance between your eyes and the lens is too large, you may feel the prescription is weak and blurry. Try to adjust the two nose pads and make them stay further and outwards to each other, which will shorten the distance. For the far-sighted (those who have trouble seeing up close), please try the opposite way.  

Issues caused by the blue-light blocking lens.

The blue-light blocking lens has a light yellow/brown basis to block blue light radiating from your electronic devices. The yellow/brown basis will make the vision darker and reduce light transmittance. Besides, the blue-light blocking lens has a blue-purple coating, which is more reflective compared to regular glasses. You may feel some glare and discomfort at first since it is a strong block, but it will disappear after a few days. The sun transmits blue light as well, so these glasses are perfect for everyday use. They are especially for those who spend a lot of time looking at a computer screen or any screen for that matter.  

The accurate prescription doesn't always mean comfortable glasses.

To process a pair of glasses, besides the accuracy, we still need to think about the balance of your two eyes’ diopters, and the comfort, etc. But sometimes you will get a prescription that only attempts to show your eye condition without considering if you want to use it to get a pair of glasses.
So if you find you are having a headache or dizzy wearing the glasses with the right prescription and proper frame, you may need to ask your doctor to adjust your prescription for eyeglasses.

First time trying progressive glasses.
It is of great importance to learn how to use progressive glasses and it may take several weeks to get used to them. If you still feel uncomfortable after several weeks, you could change to bifocal glasses or single vision for reading/distance.