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Logo of brjopthalBritish Journal of OphthalmologyVisit this articleSubmit a manuscriptReceive email alertsContact usBMJ
 
Br J Ophthalmol. 2007 July; 91(7): 988.
PMCID: PMC1955667

From the Library

“By 1625 he had begun to turn his attention to other mathematical problems and to optics, again clearly in ways that excited the admiration of Mersenne and the ‘erudites'. And rightly so, for at about this time Decartes made an important scientific breakthrough: he discovered the law of refraction. This is the law that gives a geometrical description of the behaviour of rays of light as they pass through the interface between one optical medium and another. In fact, the law had twice been discovered earlier: In 1601 by the English astronomer and mathematician Thomas Harriot, and in 1621 by Willibrord Snell, professor of mathematics at the University of Leiden. Harriot and Snell did not publish their respective discoveries; Harriot's work has only recently come to be appreciated from a study of his manuscripts, while Snell had better fortune in having his priority over Descartes recognised by Huygens in the 1690s. The law of refraction is now known as Snell's Law as a result. But Descartes, apart from discovering it independently first gave it a published mathematical description.” (Grayling AC. Descartes. The Life and Times of a Genius. New York, Walker and Co, 2005:106)

The difference in the size of various breeds of domestic dogs is striking. Investigators have now described a single IGF1 single‐nucleotide polymorphism haplotype common to all small breeds of dogs and nearly absent from large breeds. They suggest that the sequence variant is a major contributor to body size in small dogs. (Science 2007;316:112–6)

The ocular morbidity caused by Toxoplasma gondii is well known to ophthalmologists. The parasite requires two hosts, the cat and the rat. Investigators from Stanford University have now discovered that rats carrying the parasite lose their fear of cats increasing the likelihood of the passage of the parasite. This apparently is due to the fact that Toxoplasma cysts preferentially affect the rat's amygdala thus interfering with normal fear mechanisms. (Proc Natl Acad Sci 2007;104:6442–7)

Eye standards established for driving permits have been criticised for being arbitrary and not adequate to screen all potential visual contributors to automobile accidents. Investigators have now reported the findings on the study of Maryland State automobile accident records. In this study glare sensitivity, visual field loss and useful field of view test were significant predictors of crash involvement. Acuity, contrast sensitivity and stereo acuity were not good predictors of crashes. These results obviously suggest that ophthalmic standards for driving permits need to be reassessed. (Invest Ophthalmol Vis Sci 2007;48:1483–91)

Peer review is considered to be the gold standard for scientific publications. However, it has been criticised by many as being arbitrary, biased and not time efficient. Now a study comparing traditional peer review with an early screening approach involving six editors of a journal documents that decisions were more delayed for traditional peer review yet acceptance rates were similar in the two groups. Editorial screening is now the policy for this journal. (Ann Neurol 2007;61:a10–a12)

Researchers at Rensselaer Polytechnic Institute have reported the creation of a new coating that reflects almost no light. The new material consists of angled nanorods laid on top of a transparent semiconductor wafer. Refraction was reduced to as little as .01%. Although the authors suggest the usefulness of this coating for LEDS and solar cells clearly there would be advantages for this coating material in various spectacle devices. (Sci Amer 2007;296‐37)

Clinicians are well aware of the fact that many women with Multiple Sclerosis experience significant remission of symptoms of multiple sclerosis during pregnancy. Now investigators have documented a potential explanation for this phenomenon. They report that prolactin appears to regenerate myelin destroyed in a mouse model of multiple sclerosis. (J Neurosci 2007;27:1812–23)

The pathophysiology of autism has yet to be defined. However, investigators have now sequenced a gene called SHANK3 in a large group of patients with autism. Mutations were found in three families. SHANK3 encodes a protein that has an important role in neuronal signaling. (Nature Genet 2007;39:25–7)

Women facing the complications of menopause appear to be left with little in the way of medical assistance. Recent reports have suggested the risk of breast cancer associated with hormone therapy. Now, a study of herbal supplements (primarily black cohosh) has documented that herbal interventions faired no better than a placebo in relieving menopausal symptoms. (Ann Int Med 2006;145:869–79)

The advantages of multi‐focal spectacles are well known, nevertheless, epidemiologic studies have suggested that elderly people who wear multi‐ focal spectacles may have an increased risk of tripping. A report from the University of Bradford suggests that wearing multi‐focal spectacles increased the variability of toe clearance and risk of tripping during a step negotiation paradigm. The authors suggest that in elderly patients who are at high risk for falling mult‐i focal spectacles may not be appropriate. (Invest Ophthalmol Vis Sci 2007;48:1466–71)

The term vegetative state is applied to patients who although awake appear to be not aware. This is a common occurrence following brain injury. The precise mechanism of vegetative state has yet to be determined. However recent functional neuro‐imaging studies have suggested that regions in the prefrontal and parietal cortices are significantly less active than in normal unaffected controls. Thus, vegetative state may be a result of cortical damage or perhaps disruption of the connections between these cortical areas and the thalamus. (Sci Amer 2007;295:84–9)


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