You can wear the eyeglasses and contact lenses at the same time. But you should adjust the prescription of them. You have two options. One is the combination of one pair of eyeglasses with no prescription and the contact lenses with right prescription. The other one is the combination of eyeglasses and contact lenses with limited prescription. The two added prescription should be your right prescription. However, once you wear the contact lenses, you should keep notice of the hygiene. In a word, it is safe.
Yes, it may decrease the degree of sight due to the power available in eyeglasses and contact lenses. And you could get a headache and mess your eye sight up if both eyeglasses and contact lenses have prescription. However, it could be fine is your contact lenses are cosmetic type. The other exemption is the people who have presbyopia and are over 40 could use this way to improve the ability to focus. In a word, it's not advisable and not safe for you to wear them together.
Generally speaking, itâ€™s ok to wear eyeglasses and contacts at the same time. I have seen many people wearing them in the work place. But you should see your ophthalmologist to determine what your eyeglass prescription should be while wearing your contact lenses that will give you the best corrected vision. On the other hand, there are also many people who can not wear eyeglasses and contacts at the same time. Because if they wear both of them, it will make their eyes feel eyestrain. In a long time, it will damage their eyes. So you should console it with your doctor so that you can make sure if it's fine for you to wear them or not.