I cut a cotton ball in half, wet it with a little warm water, and just wipe the gunk from Garrett's eyes. If it's dried then it just rest the damp cotton on it for a few second to soften it then wipe it clean.
Sometimes, during the day, i'll have to give him a quick wipe cause I hate when his eyes look nasty.
Garrett's really good about getting his eyes cleaned, I try to do it every morning and evening when I'm brushing my teeth so it will be routine and normal for him. I clean his teeth at the same time.