Anti Mist For Specs
Bit late commenting on this thread.
But, what you are looking for is NOT a hydrophobic coating but hydrophilic coating. Hydrophilic terminology is dissolves in water. However, this type of coating attracts water and spreads it across the entire surface area. In layman's terms - Stops misting. i.e. A mirror in the bathroom that does not mist when having a shower.
I worked on a solution for this problem, my son wears glasses, for nearly two years. There is no permanent solution, atmospherics, pressure and a host of other things effect the misting effect. However, a non permanent cure is, potato juice or a product that contains Titanium Dioxide (TiO2).
Potato juice - rub raw potato on the lens both sides. Allow to dry then lightly buff off. good for a few days.
TiO2 - Some toothpastes or better Sun Screen. In both instances, use the same as the potato method.
The secret in both is allow to dry before lightly buffing to clear vision.