Does wearing contact lens upside down make a difference to the vision or spoil eye sight?

I don't think it permanently spoils your eyesight, but depending on your prescription, you probably won't see as clearly with it inside out. It will also feel like an eyelash or something is in your eye. The way to tell is, hold it on your index finger as if you were going to put it in your eye and keep it steady horizontally. Either bend down so you are looking at it directly from the side, or bring it up to your eyes so you can see it directly from the side. If it is right-side-up, it will look like a perfect little bowl. If it is up-side-down, the edges will flare out and it will look kind of "flatter." If your eyes are very bad, I would suggest wearing your glasses while figuring this out and not removing them until you are ready to actually insert the lens.

It makes a difference because a contact lens is like a slice of a sphere and only the right side has the right base curve that provides optimal fitting and minimal irritation.Mostly there should be a visual difference too. Place the lens on your finger tip and examine it from the side in both shapes.The shape with the steeper position is the wrong way to put it in.The more spherical shape is the right way.

If you have an astigmatism, the contact lense will be weighted so it is right side up. If you put it in backwards, the discomfort will let you know

Ewww, contact lenses ewww *eyes water*

If you mean a soft lens, yes you can tell the difference. if it is inside out, the lens will look like a soup bowl, it should be perfectly rounded. Y ou won't get clear vision if inside out

normally the concaved part is where your pupil goes in depened end, if not worn correctly they cause irritation, and make sure you always take them off, when you go to sleep, since it will damage your eyes by causing further irritation.

oh, I am so happy for " Irish A " that she was blessed with perfectly good eyes. isn't she wonderful. it really hurts my eyes if my contacts are inside out, like stinging, burning, as if a bug flew in there, etc. there is no right side up or upside down to contact lenses.

It is very irritating when worn inside out, so you know you have to take it out, flip it & re-insert it. You can tell the right way it should go in; if you look at the lens from the side, the edges appear sharper when the lens is inside out.

If you can wear your contact lenses reversed then you have become the first in the world. They can only go one way.