Hi, I'm searching information about the existence of optometric test in order to measure peripheral AV or any other features about peripheral vision (except measurement of visual field).
Thank you:)
You could use visual acuity charts designed for low vision. Since the central vision of patient is often affected by certain pathology, we measure the visual acuity by asking the patient to move his eye in order to use his peripheral vision to read the numbers or letters. I actually mainly use the "designs for vision" test.
To Marianne: under AV i mean "Visual Acuity", I had a mistake because in Italy we used to say "Acuità Visiva"->AV.
To Terry: thank-you for the answer about the AV:) I imagine this was the way to measure peripheral VA, but I was not sure.
What about other peripheral test? I try to explain better what I'm trying to find out: are there any test to quantify the balance problem created by an alteration of the balance between central vision and peripheral vision?
May be ERG - electroretinography will give required information
mMy be the excentric vision ? like fo? colobomatuos retina or central desaseases ?
To Marianne: it could be a good solution, but I'm not a oculist, I'm an optometrist. I'm searching a test I can use during an optometric visit. ERG will give me an answer about a retinal problem, but not about how the patient solve this problem when he's seeing something.
To Maria Marta: the list you wrote is about deseases that I can't solve with glasses. My problem is about glasses I have to create.
For example, suppose to have a person with 5D cyl x 180, who's wearing glasses with a 4.75D cyl x 180, Hoya lenses. During the visit I've done all the test to be sure he can bear this correction. Suppose that I've to change the brand because I don't buy Hoya lenses now, so I order Zeiss lens with 5D cyl.
He try this glasses, but the next week he come to my shop reporting sickness like dizziness. The centring and power were right. This could be a case alteration of balance between peripheral vision and central vision. It could be create by the geometry of the new Zeiss lens.
Now, can I foresee this kind of sickness caused by the geometry of the lens?
I don't know of any way to assess balance between peripheral and central vision. That said, it is important to remember that central vision provides high contrast, detail vision and peripheral vision provides low light and motion vision. Detail vision is not possible with the peripheral retina. In the case you mentioned, Assuming the lens material is the same between the two lenses, I would check the PD and base curve of the Hoya lenses and the Zeiss lenses to see if that is what is causing the dizziness.
Hi Greta,
In this case you just tell us, I think that might be a difference in aberration levels between Zeiss and Hoya lenses.
If the patient has a good AV in central vision but refers discomfort or other symptoms, it may be that the design of the lens is the one that generates the distortion. The Hoya lenses were mounted in a frame of equal size to the Zeiss lenses?
To Esteban: yes, they were mounted in the same frame.
So the problem could be always caused by the geometry of the lens or a mounting error..
Greta, that could be.
Therefore, it is interesting that differences like this between lenses represents presence or absence of symptoms in a patient.
I think it would be important to assess whether this occurs only in this patient or if it is something common to switch between these lenses.
I think that is not so important fact to measure visual acuity in peripheral vision; or at least not in the same way it is measured for central vision. It could be measured peripheral vision based on the visual qualities that have the rods. Perhaps perception of movements.
Hi Greta l think that adding contrast sensitivity testing especially grating CS at nuber of spacial frequencies may help you in assessment of vision quality
More than evaluating the wearer it is important to find the difference in the geometry of Hoya and Zeiss lenses. Probably aligning with the geometry of the Hoya which wearer got adapted to will be the solution out.
No doubt the evidence is not available in the literature. I have asked our optician to collect information from various lens companies.
Ok, thank you everybody for all the answer:) you helped me a lot:)
Clinical optometric tests are either limited to the fovea or use perimetry including variants like SWAP. The way around that is to use a computer-based test (i.e., where the stimulus is presented on a computer screen), and add a fixation cross off center. The fixation cross can even be outside the screen at an arbitrary eccentricity (perhaps on a cardboard). Monitoring eye movements is helpful, but with short presentation times loss of fixation is rare anyway.
You will find tests on my overview on psychophysics software:
http://www.visionscience.com/documents/strasburger/strasburger.html
or
www.hans.strasburger.de/psy_soft.html
and a scientific review on peripheral vision here:
http://www.journalofvision.org/content/11/5/13
Cheers,
Hans Strasburger
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