Illusory Stimuli Can Be Used to Identify Retinal Blind Spots

Background. Identification of visual field loss in people with retinal disease is not straightforward as people with eye disease are frequently unaware of substantial deficits in their visual field, as a consequence of perceptual completion ("filling-in'') of affected areas. Methodology. We attempted to induce a compelling visual illusion known as the induced twinkle after-effect (TwAE) in eight patients with retinal scotomas. Half of these patients experience filling-in of their scotomas such that they are unaware of the presence of their scotoma, and conventional campimetric techniques can not be used to identify their vision loss. The region of the TwAE was compared to microperimetry maps of the retinal lesion. Principal Findings. Six of our eight participants experienced the TwAE. This effect occurred in three of the four people who filled-in their scotoma. The boundary of the TwAE showed good agreement with the boundary of lesion, as determined by microperimetry. Conclusion. For the first time, we have determined vision loss by asking patients to report the presence of an illusory percept in blind areas, rather than the absence of a real stimulus. This illusory technique is quick, accurate and not subject to the effects of filling-in

Designs are cultural alloys; STEMPJE in design methodology

... the scholar who says he detests any kind of science is not only ridiculous: his attitude is decidedly harmful. Harmful because it encourages those who are responsible for decisions that may determine the fate of mankind to be intentionally ignorant about the material background against which their decisions should be taken. Harmful also because authors and scholars, while gladly using modern commodities, fail to see the philosophical implications of science and tend to deny scientists and engineers their legitimate place in culture. But we, scientists and engineers, we know that we have not only created material things and above all we know that we contribute to better relations between nations and peoples. For us it is easy to have understanding of and objective appreciation for the work of others, and from there it is not difficult to arrive also at human understanding and appreciation [H.B.G. Casimir, 1965; italics added