I should point out the the eyedroppers I use are quite long. I just peeled off the rubber bulb and the glass tube itself is exactly 4.25 inches long. Hope this helps.
Eye droppers come in many sizes. A way to roughly measure the capacity is to fill the eye dropper with water and then squirt it into a teaspoon. 1 teaspoon is ~4.93 ml. 1/2 teaspoon is ~2.46ml. 1 table spoon is ~14.79ml. I hope this helps.