Eyebathful

One drop of lemon juice in an eye-bathful of warm water is sufficient.

Eye Lotion Tablets. ℞ Optabs. Mitte x. Sig: i diss. in an eyebathful of warm water.

The following information on the use of eyebright is from Acta Phytotherapeutica, a Dutch scientific journal on botanical medicine. […] The journal reports that an even more effective method is a local application of a lotion “made from three drops of fluid extract of Euphrasia in an eyebathful of cold water.”

Use bottled spring water for bathing the eyes; use a fresh eyebathful for each eye.

Alternatively, add 1 to 3 drops of tincture to an eyebathful of distilled water. […] A few grains of salt can be added to each eyebathful.