Another issue to pay attention to is a wrong prescription when changing glasses. If you don't know how to read glasses prescription, ask! This happens when your glasses are over correcting or under correcting your vision. In this case, you won't be able to adjust to new glasses. Errors during an eye exam or errors in the measurement process or the making of the glasses themselves can all be factors leading to a false prescription.
Human errors may sometimes occur despite the mainly digital creation of lenses and a dispensing optician's meticulousness in taking measurements properly. In these cases, no matter how much time you take to get used to new glasses, you will keep experiencing issues with your vision.
As a general tip, when wearing a new pair of glasses, try to pay attention to the visual effects you're experiencing. If you notice that the visual clarity or discomfort doesn't improve within 5 to 7 days, then it can be a sign of a wrong prescription. This process may take longer with bifocal lenses or progressive lenses, so you may want to give yourself 2 to 3 weeks to get comfortable with the glasses. If these issues persist, make sure to visit your optician so that they can check the prescription or retest your vision to make sure that your new glasses are perfect for your needs.