Contacts vs Glasses

On 4/19/2018 9:08 AM, amdx wrote: snip

You're the first person I've encountered who actually tried 'em and had the skills to describe the sensation.

I'm not sure there are two signals. Let's consider only one eye.

With single vision glasses, the scene gets corrected as at passes to the retina. You can move your eye to focus another portion of the scene, at the same distance, onto the center of your retina.

With progressive glasses, you can't do that. Different parts of the lens have different "magnification". If you want to center on a portion of the scene at a different distance, you move your head so that the path from the object passes through the portion of the lens with the correct magnification.

If a portion of the scene is projected onto the retina out of focus, there isn't much the brain can do beyond ignoring input from those "pixels".

I have a "dead pixel" in my right eye. In bright sunlight, I can see the defect when my eye is scanning the scene. A fraction of a second after the movement stops, the brain has ignored or interpolated the defect.

For contacts, you can't change the relationship between the lens and your retina. If you could read a book, you'd expect distance vision to have a fuzzy hole in the middle of the image.

Imagine looking down a long hallway. You'd expect to be able to see what's at the end and the walls along the way. I'd expect multifocal contacts to do just the opposite. You'd have near vision in the center and far peripheral vision. With progressive glasses, I can't see the whole scene in focus, but I can move my head to see any part clearly in the center of vision. With contacts, you can't do that.

And when you go outside into bright sunlight, your pupils contract and you'd have nothing but the fuzzy center.

When you open both eyes, the issues multiply.

I'd be much appreciative if you could describe in some detail the artifacts associated with multifocal contacts.

I don't have a problem using readers for reading or the computer, but I'd want a clear image with low eye fatigue.

I have not been able to imagine a scenario where multifocal contacts could work for anybody. But they must work for some, or they wouldn't be on the market.

What am I overthinking?

I think you misunderstood my question, "How does your brain merge two signals (from two eyes) that overlap?"

Sorry, But I didn't experiment much beyond, S#!^ I can't see the computer with these, doesn't do me any good, Move on.

I have experimented with pinhole glasses and they do improve you vision I sometimes watch poker on a smaller tv form about 10ft, I can't see the lettering in the corner showing the odds. With the pin hole glasses it is very readable. Sometimes I will even use my finger and thumb to create a tiny hole to get a better view. Has to be tiny.

Sorry, don't have them.

I don't have much more I can relate. I see they recently came out with contacts that darken when in high light situations, they are like Transition glasses. I will probably try them in a year, when my recent order of contacts runs out. Mikek