Double vision occurs when a person perceives two images of a single object. These duplicated images can appear side-by-side, one above the other, or diagonally. Seeing double can be disorienting, affecting depth perception and making everyday activities like driving or walking challenging and potentially unsafe.
Temporary Double Vision and Adaptation
Experiencing temporary double vision is common when first wearing new glasses, especially with significant prescription changes or progressive lenses. Your brain and eyes need time to adjust to the new way light enters and is processed, a normal part of adapting to updated eyewear.
During this initial phase, you might notice symptoms such as blurry vision, mild headaches, eye strain, or a “fishbowl effect” where straight lines appear curved. This adaptation process typically resolves within a few days to two weeks. Consistent wear of the new glasses can help speed up this adjustment.
Prescription and Lens Issues
Glasses can directly contribute to persistent double vision if parameters are inaccurate. An incorrect prescription, whether too strong, too weak, or with imprecise astigmatism correction, can cause distorted or double images. This forces the eyes to struggle in fusing separate images into a single, clear perception.
Improper lens centration, where optical centers are not aligned with pupils, is another common issue. This misalignment can induce unwanted prismatic effects, leading to horizontal, vertical, or diagonal double vision. Damaged lenses, such as those with scratches, distortions, or manufacturing defects, can scatter light and disrupt image clarity, resulting in seeing double. Some progressive lens designs might also present a greater challenge for adaptation, potentially causing visual discomfort and double vision.
Underlying Eye Conditions
Sometimes, glasses reveal an existing, underlying eye or health condition. Double vision can be a symptom of binocular vision problems, where the two eyes do not work together effectively. Conditions like strabismus (eye misalignment) or convergence insufficiency (eyes struggle to turn inward for near tasks) can manifest as double vision. New visual clarity from glasses can make previously compensated issues more noticeable.
Other eye conditions can also lead to double vision. Cataracts, a clouding of the eye’s natural lens, can scatter light, causing monocular double vision even with corrective lenses. Dry eye syndrome, with an uneven tear film, can also disrupt clear vision and lead to double images. In these situations, double vision is a symptom of the underlying condition, not the glasses.
When to Seek Professional Help
If you experience double vision with your glasses, seek professional guidance. If it persists beyond the typical adaptation period (a few days to two weeks) or began immediately with new glasses, contact your optician or optometrist. They can re-evaluate your prescription, check the lens fit, and ensure proper alignment.
Consult an ophthalmologist or seek urgent medical attention if double vision is new, sudden, or accompanied by other symptoms. These include severe headache, dizziness, eye pain, muscle weakness, slurred speech, or confusion. Such additional symptoms could indicate a more serious underlying health issue requiring immediate evaluation.