Allergy eye drops needs to be absorbed and soaked in for it to work or it just enough to hit the surface of the eye externally?

Eye drops: The more the medicine gets absorbed the more effective the outcome will be.

Let It Soak(No Joke): Needs to be absorbed in order to get into the blood vessels and tissues. See what number of drops you can put in before it starts to drip out. Then put that amount in and keep head tipped back or lie down for a few minutes to help is soak in. you may need to repeat it once or twice, depending on how bad you are. If you put a lot in, some may drip into your nose backwards from the tear ducts.

Yes: I routinely advise my patients to keep the eyes shut for 20 seconds after using eye drops.

Yes Better Soaked: Yes it better to be soaked and absorped to be effective

Made you blink!: My patients find the best method is lying on their back facing upward, eyelids closed, and placing a drop at the edge of the lid near the nose and letting it roll into the eye slowly. Otherwise standing up, tipping head back and dropping it in is hit or miss; good chance eyelashes will blink the drop away - like Nadal poaching away a weakly hit groundstroke (except yesterday at the French Open!).

Apply topically: Anti-allergy drops are calibrated to penetrate the eye to the proper level. You do not have to do anything to cause them to "soak" into the eye as they will do this by design. If you eye irritation and redness is due to allergy, then these types of drops will fairly rapidly b e effective.

Yes: You do have to apply the drops correctly for them to work. They do have to reach the surface of your eye (the white part or conjunctiva). You cannot simply drop them on to the outside of the eye-meaning the skin or eyelids. There are several types of prescription eye drops that work very well to control allergic symptoms when used correctly

Allergy eye drops: There are many classes of allergy eye drops from drops that are antihistamines, anti-inflammatory, combination of 2 drugs, emollients and blood vessel constrictors to name a few. Each have different mechanisms of action, most are designed to work quickly. It is important know of side effects with the blood vessel constrictors and the anti-inflammatory subset of eye drops.

Yes: Generally, if the drop touches the eyeball anywhere, that will be enough for it to achieve its effect.