Accidentally leaving eyeglasses in a refrigerator for a few minutes while the door is open should not cause any significant damage to the glasses. Eyeglasses are generally designed to withstand various environmental conditions, including changes in temperature and humidity. Here's what might happen during this scenario:
Fogging: If the temperature inside the refrigerator is much cooler than the room temperature, the eyeglasses may experience some condensation or fogging when taken out. This is because the cold glasses come into contact with the warmer air, causing the moisture in the air to condense on the lenses. However, this fogging is usually temporary and will dissipate as the glasses adjust to the ambient temperature.
No permanent damage: Assuming the refrigerator is functioning correctly, leaving the glasses inside for just a few minutes with the door open should not cause any permanent damage to the lenses, frame, or coatings.
To avoid any potential issues, it's a good idea to wipe off any condensation gently using a soft, clean cloth when taking the glasses out of the refrigerator. Avoid using hot water or harsh cleaning agents on the lenses, as this could potentially damage lens coatings.
In general, eyeglasses should be stored in their case when not in use to protect them from scratches and accidental damage, rather than being left in unexpected places like the refrigerator. But, as a one-time accident for a few minutes, there's no significant cause for concern.