Ocular surface

Tears, blinking and the dry eye

With every blink, a three-layer tear film spreads again over the eye. Between two blinks (every 4 to 6 seconds), that film has to hold. Start the animation, or drag the time slider:

The surface of the eyeComfortable

Surface of the eye and tear film stability

The tear film, in cross-section

cornea
Lipid — the oil (Meibomian glands), limits evaporation
Aqueous — the water, hydrates and nourishes the cornea
Mucin — anchors the film to the surface of the eye
Time since the last blink 0.0 s

The film breaks up (BUT) at around 10 s here · the blink comes at around 5 s.

What dries the eye out

Screens — we blink 2 to 3× less Age, hormones Dry air, air conditioning Contact lenses

Educational diagram — Dr Moïse Tourabaly, ophthalmologist. For information purposes; does not replace an examination.