Tilting my glasses down corrects my keratoconus completely. So possible to correct by changing prescription?

[fuzzybabybunny]

The 'E' photo is what I see with my right eye with my glasses.



As you can see, there's a second ghost image that occurs. It is superimposed a little bit down and towards the right of the primary image.

My prescription is (SPH) -2.75 (CYL) -0.75 (Axis) 171

I noticed that if I tilt my eyeglasses down (see photo) I can see *perfectly* through my right eye. All the ghosting is gone.



What could this indicate? Is there any way I can adjust my prescription so that I can see perfectly, since simply tilting my glasses down results in complete correction?

I understand that by tilting it the light basically goes through more lens material to reach my eye, so would a high index lens plus a lower diopter on the CYL work?

Maybe decreasing the diopter of the cylinder to something like (SPH) -2.75 (CYL) -3.50 (Axis) 171?

[Anne Klepacz]

I suspect only an optometrist could give you an answer to this. But it's a bit like the experience many of us have had, of pushing the eyelid up and finding all the distortions had gone. Glasses often can't correct KC vision because of the shape and location of the KC cone. But rigid contact lenses, which create a regular surface for the light to hit, would probably make a big difference to your vision.

[Ali Akay]

Hi
This is a tricky one!
Keratoconic corneas often have what is called "high order aberrations" which cause the ghosting you're getting with your glasses. You've found, by experimentation, that tilting your glasses down clears the ghosting. This is due to the image formed by the tilted lens somehow reducing the "high order aberrations". The problem is that it's very difficult to replicate this effect simply by altering the prescription of the lens. The effect is not due to light travelling longer distance, etc.


There are some bespoke spectacle lenses designed by using an "aberrometer", but there isnt much evidence of them being of great benefit for KC. They may give you sharper vision when you're looking "dead straight", but you would probably lose the benefit when you look around. Contact lenses are much more effective as they stay centred on your eyes and move with your eyes.

I am sorry I havent been of much help! Zeiss have an instrument called "i-profiler" which is one such system, but I dont know any keratoconic patient who has tried it and found it beneficial. If you want to give it a go, look out for an Optometrist that has a "Zeiss i-profiler" and give it a go and let us know how you get on. However, be aware that they wont be cheap, and may not make much difference!