Halos and starbursts
Lights grow rings and spikes at night.
These demonstrations illustrate ideas about vision. They do not reproduce another person's experience, measure your eyesight or diagnose an eye condition. Real vision varies with the person, the lighting, the task and the surroundings.
Halos and starbursts
Light scatters inside the eye when the lens or cornea is not clear, or after some eye surgery. Oncoming headlights and street lamps are where people notice it most.
Tell your optometrist if night driving has become harder. Halos with a painful red eye or sudden blur need urgent advice the same day.
A screen cannot reproduce real glare. The spread is a graphic effect on the brightest parts of the picture.
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Related guides: Cataracts, Keratoconus
Read the original sourceWhen the light changes, sight needs time
A change in the light can bring several difficulties at once. Cones handle detail and colour in brighter light. Rods handle dim light. Cone-rod dystrophy often affects cones first, with rod difficulties developing later, and the balance differs from person to person. Slow adjustment and a lasting problem in dim light are two separate things. Extra time helps with one but does not remove the other.
Think of walking into a hallway from a sunny street, or leaving a dim cafe. The difficulty changes while you stand in the same spot. Tell your eye-care team about both directions: what is hard straight away, what gets easier with time, and what stays hard.
This is a designed teaching sequence, not a measured adaptation curve. A 15 or 60 second playback is a demonstration length, not a prediction of how long anyone takes to adjust. A washed-out screen cannot reproduce light sensitivity or pain. Nothing flashes, and the rest of the page stays unchanged.
Sources checked 5 October 2026: RNIB: inherited retinal conditions, MedlinePlus: cone-rod dystrophy, Macular Society: cone dystrophy.
Beyond the picture
A change in sight can affect reading, getting around, work and recognising people. Choose a condition above for everyday examples and ideas to raise with your eye-care team.