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Dr. A.S. Desai
Dr. A.S. Desai, Ophthalmologist
Category: Eye
Satisfied Customers: 2405
Experience:  MS Ophthalmology with 13 years of surgical expereince
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Tunnel vision:: (problems with peripheral vision): can a

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Tunnel vision:: (problems with peripheral vision): can a person with say moderate
tunnel vision, say 90 degs (45 + 45) = half of a "perfect" 180 degs,,,
who has to
1) turn his entire head to left or right, to see some object vs
2) turn only his EYES toward the object, to see it
,,,is he/she considered to have "better vision" if can do #2 rather than having
to do #1? I do not have good perf vision, never did, but e.g. I can see an object to my far left
(or right) if I move my just my eyes to the left or right,,I need not turn my head 90 degs
to do it!! Am I "better off" than one who has to move his head a full quarter turn
to see an object!?
Hello,

Welcome to Pearl.com

The image would fall on the macula ( most important seeing area on the retina) either ways- if a person turns the head or turns the eyes. Both would be the same and the latter would not be better of. But the problem you have mentioned becomes significant in a person who has aphakia ( absence of lens) and is wearing thick aphakic glasses. In such as case merely moving the eyes would not help to improve the vision and the person has to move his head in order to see better ( it ensures that the person is looking through the glasses only).

You are able to see things to the extreme right or left of you by moving your eyes alone is because the image falls on the central part of the retina on moving the eyes . In your case the central part of retina is functioning well which is why you are able to see better on moving eyes . The justification of a person having better vision only because he can see with moving the eyes alone and not the head may not hold good in your case.

Please feel free to ask follow up questions if any.


Thank you and best wishes.


It was a pleasure to have answered this question.

Experts are credited only if a positive rating is given and not otherwise. So do remember to give your rating. A positive rating is what I aim for and we can continue to interact till you get a satisfactory response.An excellent feedback and /or bonus are most welcome and appreciated.

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Customer: replied 4 years ago.

That helps, thank you. Is there a chart, table, etc somewhere that gives the/a
"scale of Perf Vision with the degrees value"? E.g., only a 20 degs of PV is
not good at all, a 90 degs of PV is what,,,fair to poor? a 180 degs of PV is very good,
ie, what --words-- describe the amount of PV ability, from say 20, to 90, to 130, to 180?
Let me know if I am making myself clear here! what "description" (poor, ok, good, etc)
goes with what value of PV in degrees?
I read somewhere that humans, in general, do not have good PV,,,,where as many animals
have excellent PV. thanx

Hello Robert,

Thank you for the reply .

You are absolutely right about some animals having better peripheral vision than humans.

There is a vision impaiment chart which tells us about the amount of visual impairment with respect to the visual field( degrees from centre or point of fixation).

http://www.news-medical.net/health/Types-of-visual-impairment.aspx

Read types of visual impairment( degrees of visual field is mentioned here but it corresponds to remaining ,useful central vision).

Most of the vision is expressed in terms of good central vision and not in terms of peripheral vision. This is however detected only by perimetry or visual field analysis.

Thank you and best wishes.


It was a pleasure to have answered this question.

Experts are credited only if a positive rating is given and not otherwise. So do remember to give your rating. A positive rating is what I aim for and we can continue to interact till you get a satisfactory response.An excellent feedback and /or bonus are most welcome and appreciated.

Views expressed are for information purpose only and cannot substitute a visit to an ophthalmologist



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