Fusional Reserves (eyes)

[JustFlyin']

I have just found out that I have no fusional reserves.
Apparently this means I have no depth perception. I have never noticed this before myself.

Now, my question is how would this affect my medical?
Both FAA and Jar.


Thank you for any info.


PS. I currently hold a Jar Class one and an FAA class one medical.

[Jimmy The Big Greek]

this is strange. If you do not have fusional reserves then you must be experiencing "double vision" or you have a supression.
Can you tell what kind of test you did which found you with no "fusional reserves". Was it a test with a red lence or glas bar (prism bar).

And yes If you have no fusional reserves you have no stereopsis (depth perception), its like having two cameras taking different pictures and are not fused on the same object.

If you do not have fusional reserves it could be like my freind that has strabismus (squint). I do not know what the requirements are for this.

[JustFlyin']

It was the test with the red lens which prompted furhter testing.
It was determined that I cannot see 3D. However I feel that I have no problem with this and I certainly don';t see double.

[Jimmy The Big Greek]

Ok most likely you have a supression. This means that you have one eye that is dominant. Basicly in aviation you don't need to have full stereopsis because it works up to about 20 meters only.

Unless you have any squint I don't see that it is a problem, although I'am not a medical doctor.

I know that the FAA is a bit more picky about this, but I'am pretty sure that you would pass with a waiver.


According to FAA regulation you would get denied a medical and be required further evaluation. As I said before most likely that you would get a waiver.
Your condition is called:
"Suppression sufficient to prevent determination of heterophoria"
and most likely you have squint that causes this.

The strange thing is that you already have JAR and FAA first class medical and they haven't noticed it before??? I would suggest that you try to go to another doctor or an optometrist.

[JustFlyin']

Thanks for this info, I feel a little more comfortable about it now.
Fortunately this is not for my JAR or FAA renewal but for another initial medical for a third licence. So my JAR and FAA won't be affected (for now).

Regards, JF.

[Flyin'Dutch']

This is a bit of a funny one as it is the only thing which I can think off where the FAA is a bit more strict than the CAA/JAR.

There are 3 degrees (levels) of fusion. Heavily jetlagged at the moment so can not be bothered to get the book out to split them up but basically for good stereoscopic (3D) vision you need all three.

The FAA requires heterophoria testing for classes 1 and 2 and not 3 (for which the only requirement is that you don't have diplopia (double vision).

If you hold an FAA class 1 you must be within 6 diopters exo/esophoria (=propensity to squint out/inwards) so I would not worry too much about this.

Interestingly enough the lack of stereoscopic vision seems to give less problems than may appear at first sight (forgive the pun!)

1. Stereopsis is only useful up to about 2 meters, beyond that even people with full stereopsis rely on experience and

2. People without steropsis use experience for distance judging.

The latter is the reason why people don't have trouble with driving cars even without 3D vision.

People who only have one eye (and therefore no 3D vision by definition) can be certified by the FAA but only by doing a flight test for an FAA examiner whereby they need to demonstrate they can judge distances adequately.

HTH

FD