Dry eyes. When the eye's surface is too dry, it can become irregular, and light entering the eye can scatter. This can cause you to see halos around lights, especially at night.

What causes you to see halos?

Seeing halos around lights is a result of diffraction, an effect that occurs when the light bends while entering the eye. Diffraction can sometimes be caused by glasses and contact lenses, but it can also be a disease's side effect.

Can dry eyes cause weird vision?

People with dry eyes may experience irritated, gritty, scratchy or burning eyes; a feeling of something in their eyes; excess watering; and blurred vision. Symptoms include: Redness.