What closed eyes change
When the eyelid closes, oxygen supply drops to roughly a third and tear exchange nearly stops. A lens that is comfortable all day can starve the surface overnight.
Which lenses are approved
Only lenses with an explicit overnight or extended-wear approval. Coloured lenses are generally not in that category, and the pigment layer reduces oxygen transmission further.
If you fall asleep in them
Remove them as soon as you wake, do not wear lenses again that day, and watch for redness, pain or blurred vision. If symptoms persist for more than a few hours, get the eye examined.
Naps
A short nap in daily lenses is lower risk than a full night, but the same rule applies: the lens was not designed for closed-eye wear.
Frequently Asked Questions
Can I sleep in daily disposable lenses?
No. Daily lenses are designed for waking hours only.
What is the worst that can happen?
Corneal infection, which can progress within 24 hours and in rare cases causes permanent scarring.
Can I sleep in them if I have done it before without problems?
Risk is cumulative, not a per-night certainty. Previous luck does not make the next night safe.
