The participants are randomized into 2 groups. For group I; the participants will be instructed to use the Eye Drop Guide first while for group II; the participants will be instructed to use the routine self-instillation technique first. The instruction will be given to all participants by the same investigator. The participants are allowed to practice until confidence in the techniques to which they are assigned. The participants then are instructed to use only that technique to instill eye drops in both eyes every day and keep the diary to document the date, time of practice, and number of bottles use in each eye for practice at home. The investigators make a telephone visit at 1 week to remind the practice routine and the follow up schedule. The 2 week follow up will be scheduled to evaluate the self-instillation performance using the techniques to which they are assigned by the VDO recordings under the same setting as Day 1.