Proceedings of: Workshop on Improving Building Design for Persons with Low Vision

Discussion

Question by [Participant]: The concept of glaucoma affects glare. Is that correct? Is that because it diffuses the light in the fluid of the eye?

Response by Bob Massof: No. Two things seem to affect glare. One – and you guys will correct me – one is optical. So if a glare source is off axis for anybody – it doesn’t have to be somebody with low vision – it’s called disability glare. That’s just scattered light inside your eye. Okay, the light hits the back of the eye and bounces around inside the eye and it causes what’s called veiling luminance and that washes out the contrast of the image. Okay, so that’s a form of disability glare. For anyone who has something wrong with the optics, whether you have dirty glasses or your tear film is too full of mucus, or there’s something that is having optical affects, that scatter gets even greater. If you have a cataract, especially nuclear sclerosis, you get even more scatter. So those types of things just wipe out the contrast. It will wash things out just from having that glare source there. That’s from having just a bright light that’s in the line of sight – even if you’re not looking right at it, it’s off to the side – if it’s visible, the light is getting in through the pupil and it’s going to have an effect. Now, people with glaucoma do get cataracts. But also, there’s some neural adjustment that occurs – being able to compensate for the scattered light neurally in the retina. Glaucoma is one of the conditions that can [cause patients to] become more sensitive to glare, as well as macular degeneration.

Question from Fred Krimgold: I noticed that the tests you referred to are all static. And one thing that I was concerned about is that vision in a dynamic situation, like traffic or mobility, is very different from simply accumulating cues and being able to read a chart. Are there measures that give you a sense of that dynamic function in vision?

Response by Bob Massof: Well, there are measures. Certainly, a number of measures that are used in research studies, used in a laboratory to study the dynamics of vision. There are not very many clinical measures. But in many cases, you’re really not trying to answer that question. It’s more you’re trying to deal with identifying the stage of the disease or the impact of the disease on the vision. So these are used as indicators of where –

Comment by Fred Krimgold: Well, the particular case is that the driving test is a static test. Driving is not static. And also, as you mentioned, mobility. When we look at wayfinding and other situations in which low-vision people find themselves, they’re adequacy or their functionality is dependent on being able to function in a dynamic situation, which is quite different from the measured static situation.

Response by Bob Massof: Right.

Comment by Vijay Gupta: Over the years when I [have had] – according to what I heard – my low vision for 30 years. And I’ve been through John Hopkins, through NIH and many other places, but what I’ve found [is] a big disconnect between the medical profession and the design community of buildings. That’s the basic comment that I have, because I will get into more a little bit later.

Performance and Productivity

Comment by Tom Williams: It’s interesting to me that there doesn’t seem to be any more research out there on the connection of daylight to productivity. That’s almost amazing, that scientifically there isn’t any kind of support for that.

Response by Mariana Figueiro: Measuring productivity is really hard.

Comment by Jeanne Halloin: The Heschong-Mahone Group out of California has other daylighting research on productivity, both in schools, and then they also did one in Wal-Mart where in the daylit areas, no matter what was being sold there, they sold like 50 percent more in the stores. So I think there are two other studies that -- if we want to start talking about daylight -- that we could look at.

Response by Mariana Figueiro: Actually, that study was the one with the schools that the National Academy questioned. So there’s still some debate about the Heschong study. Some people agree with it; other people still have some questions about the data, how the variance explains the data and so on. In [the Heschong study] with performance in offices, they weren’t able to replicate with daylight. Measuring productivity is really hard, especially measuring productivity in the field.