Minnesota Flyer - Serving Midwest Aviation Since 1960

By Dr. James D. Lakin
Minnesota Flyer 

Aeromedical Forum: October 2015

Vision update: To see or not to see

 


“If you want keep her on the runway it helps to see the centerline.”

Supporting this truism, the FAA has a maze of regulations to make sure that the intrepid pilot can locate the runway environment. So let’s look at a few common questions airmen ask about their eyeballs.

“First of all, just how good does my eyesight have to be?”

It depends. For a Third Class Medical Certificate which is all you need unless you’re flying for compensation, you have to see at least 20/40 in both eyes for both distant vision and near vision. If you need glasses to pass either requirement, your Certificate will have the restriction that you must wear corrective lenses for distant vision and/or possess lenses for near vision. The vision requirements for a First and Second Class Medical are the same. You need to see 20/20 in both eyes for distant vision, 20/40 or better for near vision. Your intermediate vision will also be tested. That’s how you see at arm’s length. It also must be 20/40 or better in both eyes.

“By the way, what do those numbers they use to measure my vision mean?”

In the expression 20/x vision, the first figure (20) is the distance in feet between the airman and the chart, and the second figure (x) is the distance at which a person with “normal” visual acuity would just be able to read the funny letters. Thus what’s considered “normal” or “average” eyesight is 20/20. If you are an eagle eye you might be able to read 20/15 or 20/10, meaning that you can read the letters at 20 feet that a normal guy would be able to read only if he were 15 or 10 feet from the chart. Likewise, if you’re blind as a bat you might end up 20/100 or worse! A lot of AME’s instead of using an eye chart on the wall will use one of several machines that approximate a real life chart at 20 feet. These machines can measure a lot of other things like visual fields. That’s why they are popular.

“What do I do if I can’t pass the vision test?”

You may have a future as a baseball umpire. Alternately you can run down to your local eye doctor and have her refract a new set of eyeglasses or contacts for you and try the vision test again. It’s not uncommon for an airman come in that hasn’t had his vison checked in some time. When he finds out his eyesight is not up to snuff he has 14 days to get his lenses fixed and prove to us he can read those funny letters. If he doesn’t get back to us in 14 days we have to defer him to the FAA Medical Division. They’ll write and ask him to do the same thing we did. Now however it may take two or three months or so to get the medical certificate. Not good. Student pilots only have 7 days before the exam has to be sent off to the FAA as unsatisfactory. Unless you are pretty sure your vision is within standards, have your eyes checked by an optometrist or ophthalmologist before you go for your flight physical. It wouldn’t hurt to have him to fill out FAA Form 8500-7 Report of Eye Evaluation to bring to your AME.

“Is it OK to wear contact lenses?”

Yes, except for one type, used by some people that have trouble with both distant and near vision. One contact lens is refracted to help with near sight and the other lens is set up for far vision. The NTSB felt that wearing these so-called monocular contacts was contributory to a pilot dropping an MD-88 below the visual glide slope, landing in the rabbit ears short of the runway back in 1996. Since then they have been prohibited for flight. You’ll be asked about this in Question 17b on your Medical Form 8700-8. Read it carefully and answer “no” if you wear contacts but not the near vision/monocular kind. If you do have them, use something else—glasses or regular contacts with or without bifocals—when you fly.

Bottom line: If you are unsure of your visual status, check with you eye doctor before your flight physical. If you want more information the FAA has a nifty pamphlet you can download.

Fly wisely. See you next month!

As always, comments, questions and suggestions are welcome: jdlakin@mnallergyclinic.com.

 

Reader Comments
(0)

 
 

Powered by ROAR Online Publication Software from Lions Light Corporation
© Copyright 2018

Rendered 08/15/2018 16:42