Causes of blurred vision with new glasses
Glasses are usually prescribed when you have myopia (nearsightedness) or hyperopia (farsightedness) or astigmatism. Also, if you are 40 or above 40, you may also be given glasses to help you see clear at near. When you get a new pair of glasses and they are causing blurred vision, distortions, headaches, or double vision, you might think that your glasses were not made correctly or you might need a redo of an eye exam for glasses. One or both may be true in your case, but there are also other reasons why you do not see clearly with new glasses.
The following are the three most common reasons for blurred vision with new glasses.
1. Glasses were not made correctly
Sometimes it is possible that you were given a wrong prescription or your glasses were made wrong. Your vision can be blurry far away or near. You may also notice blurred vision in one eye and clear vision in another eye. If you have astigmatism and the axis of the lens is not correct, even a small variation can cause significant blurred vision, dizziness, distortions, headache, and double vision. You should also check the bridge on the frame of glasses. The bridge should comfortably rest on your nose because it allows you to look through the optical center of the glasses, the spot for clear vision. You should see your eye doctor to make sure the prescription and your glasses match.
2. First-time wearer and adjusting to new glasses
If you are a first-time wearer, you might get asthenopic symptoms with your new glasses such as headache, double vision, distortions and eye fatigue or strain. Adjusting to new glasses takes from a few days to few weeks. You might also notice blurry vision with progressive lenses until you are used to wearing it. In some instances, when your prescription is strong, you might be having headaches, blurred vision, eye strain etc. This is why your eye doctor gives you small prescription and increases its strength in increments to help you eventually adjust to the full prescription. Glasses that have cylinder lenses (given for astigmatism) might take a few weeks to adjust.
3. You have other eye conditions
Lack of tears or low quality of tears can lead to dry eyes. One of the main functions of tears is to keep the surface of the cornea smooth for clearer vision. When you have dry eyes, you might notice blurred vision even with new glasses. There are many causes of dry eyes including the history of LASIK eye surgery, Cataract surgery etc. (Learn more about dry eyes)
Scars on the cornea can result from previous eye infections or eye injuries. When you have scars on the cornea, it loses transparency, which does not allow the light to enter the eye and causes blurred vision. New glasses can not overcome vision problems.
In normal eyes, the natural lens allows the light to pass through it and focuses on the retina. When the lens becomes cloudy, the light can not go through it, and which causes blurred vision in the affected eye. Therefore, glasses will not help you see better when you have cataract. This is why your eye doctor advises you to wait until cataract surgery to get a new prescription for eyeglasses.
Glaucoma affects the peripheral vision. When you have glaucoma, you might see clearer with glasses in your central vision but your side vision may be blurred.
Previous eye surgeries
You might still be having post-surgical complications from your previous eye surgeries. If you have corneal opacities, traumatic cataract, retinal detachment etc. as the result of previous eye surgeries, your vision is not likely to improve even with new glasses. If you had a cataract surgery done in the past, you might still have post-cataract complications such as cystoid macular edema, posterior capsule opacity etc. and until these conditions are treated, your vision remains blurred and no glasses can help.
Diabetic retinopathy is a condition when the fine vision center of the retina known as macula is affected by diabetes. Severe form of diabetic retinopathy can cause the swelling of the macula, which results in blurred vision. When you have this condition, your vision might not improve with glasses. Blood sugar is also related to your vision. When blood sugar is high, metabolic changes can occur in the natural lens, and which causes to change the refractive power of the lens. So, if you got a new pair of glasses and your blood sugar level is high, you will notice blurred vision.
Age-related macular degeneration
This is an age-related condition which causes the cells in the macula (a part of the retina) to die. When you have AMD or age-related macular degeneration, you tend to lose your central vision and glasses can not treat this condition.