There are many causes of watery eyes, but broadly one can develop watering due to over production, or under drainage of the tears from the eye surface. Sometimes the lacrimal gland will produce too many tears in certain circumstances (e.g. windy/dry conditions) which leads to watering, or sometimes there is an abnormality of the eyelids themselves, or commonly there is an impairment to drainage anywhere from the collecting ducts down to where the tears drain into the nose.
If the cause of the watery eye is due to a poor tear film (dry eye) or due to blepharitis, then it may be the case that simple measures such as lid hygiene advice, or lubricating drops may improve the symptoms. These treatments work because they reduce irritation around the eyelids, improve the tear film quality, prevent evaporation of tears, and so prevent what some people term “reflex epiphora” which is watering secondary to a dry eye, or poor ocular surface.
If the cause of the watery eye is secondary to eyelid position, then sometimes small procedures to improve the eyelid position, or tighten the lower eyelid may improve the watering. These can often be done under local anaesthetic. These can sometimes improve the position of the inferior punctum ( lower tear collecting duct).
Sometimes if the lower collecting ducts of your eyelids (puncti) are too small, then a very small procedure can be done to widen these to allow easier drainage of tears from the eye surface and hence reduce watering.
If it is the case that the cause of your watering eyes is secondary to a blockage further down the tear collecting ducts, then an operation called a DCR (dacryocystorhinostomy) may be appropriate, which creates a “short cut” for the tears to drain into the nose, rather than going down the nasolacrimal duct (NLD). The success rate of this operation can range upward of 80-85% depending upon the site of the blockage and any pre-existing conditions.