Normally when you blink, your eyelids distribute tears evenly across your eyes, keeping the surfaces of the eyes lubricated. These tears drain into small openings on the inner part of your eyelids (puncta). If you have ectropion, your lower lid pulls away from your eye and tears don't drain properly into the puncta. The resulting signs and symptoms can include:  Watery eyes (excessive tearing). Without proper drainage, your tears may pool and constantly flow over your eyelids. Excessive dryness. Ectropion can cause your eyes to feel dry, gritty and sandy. Irritation. Stagnant tears or dryness can irritate your eyes, causing a burning sensation and redness in your eyelids and the whites of your eyes. Sensitivity to light. Stagnant tears or dry eyes can irritate the surface of the cornea, making you sensitive to light. 
normally blink  eyelids distribute tears evenly across eyes  keeping surfaces eyes lubricated  tears drain small openings inner part eyelids (puncta)  ectropion  lower lid pulls away eye tears don't drain properly puncta  resulting signs symptoms can include:  watery eyes (excessive tearing)  proper drainage  tears may pool constantly flow eyelids  excessive dryness  ectropion can cause eyes feel dry  gritty sandy  irritation  stagnant tears dryness can irritate eyes  causing burning sensation redness eyelids whites eyes  sensitivity light  stagnant tears dry eyes can irritate surface cornea  making sensitive light
ectropion