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Westheiner (1965) describes a method to measure the curvature of the cornea based on scanning rotating a cube of leucite. The time between the two readings recorded on an oscilloscopic screen are functions of the radius of the curvature. Ludlam e Witteberg (1966) compare all methods proposed till now and summarize the situation in 4 points:

• the corneal surface is convex and aspheric
  
• the surface is continuous so that also the mathematical expression is continuous
  
• the maximum curvature at the top tends to reduce towards the edge, till the pre-limbarian areas
  
• the intersection of the cornea is not circular
  

Comparing the techniques based and those not based on reflection, one can conclude that the photokeratoscopy presents less errors.
At the end they examine the theories for the acquisition and analysis of the photo-kerato-scopic data.

Millodot (1969) sustains that the cornea is spheric in an area of 4 mm of diameter. Outside this region, the cornea flattens towards the outside, reducing the aspheric aberration of the eye. When applying a contact lens, the anterior surface of the cornea is replaced by the lens, increasing significantly the spheric aberration.
Comparing the effects of glasses and contactlenses, aspheric surfaces are proposed for the latter.
El Hage (1970-1972) proposes a modified version of the photo-keratoscope, where, using a sequence of rings, the exposure time is limited to 0.01 sec., obtaining an excellent precision.
Lotmar (1971) proposes a model of the eye in which the surface of the cornea consists of aspheric surfaces with a rotational symmetry.
Millodot and Lamont (1974) consider the effect of a spheric contactlens and find that it does not change the peripheral astigmatism.

CONCLUSION
We terminate here this historical revision from a birds eye view. The cornea has caused a lot of work and thoughts for more than 2 centuries and now still many questions remain unanswered. We have to understand that it is difficult to understand how the cornea is made and justify its complex role in the functioning of the eye.

Source Luce e Immagini, by Prof. Sergio Villani and Prof. Luigi Santalucia.
Related article: Brief history of the determination of the cornea’s shape (8/9)

Canadian researchers have created a prototype of glasses that avoid the loss of equilibrium, sometimes caused by progressive lenses worn by elderly persons.
Jocelyn Faubert, professor of the Ecole d’Optométrie of Montréal, has discovered that persons with an unstable equilibrium conserved a better equilibrium when they listen to “white noise”. It is a uniform sound like the hissing of the TV or the sound of waves. He has demonstrated that this type of noise enhances the perception of contrasts and also the tactile sensation. Jocelyn Faubert has therefore fixed a receiver on a frame that diffuses white sound and is now designing the equipment to integrate this device. According to his research, glasses that produce a uniform vibration could have the same property. The effectiveness of this other method remains to be seen, he declares.

Source b2eyesmagazine di September 2007

Reynolds (1959) studied the corneal profile using a keratoscope and entrusting the data retrieved from the photographic images, producing a total picture. In particular, the corneal temperature and the hour of the day influence the curvature of the periphery more than the central area.
A new method of topographic examination has been proposed by Bonnet e Crocet (1960).
It is a modification of the Zeiss ophtalmeter which allows to measure a large area of the cornea.
Fry (1961) considered the cornea like a conical surfacea with a spherical central part.
Grovenor (1961) proposed a modification to the existing keratometers and performed studies on a large population. It results, on average:

• a diameter of the optic cap of 5mm
  
• a decenterment of the optic cap of 0.5mm at the temple side and non vertically
  
• a general flattening of D (from 1,5 to 7 D) upwards and from 2 to 7 D downwards
  

Knoll (1961) modifies the keratoscope using as object a cylindric surface with a series of 11 rings. The precision of the measurement is of +0.2mm. The eyes are subdivided in 4 groups, according to the symmetry and the speed of flattening.
Noto (1961), using the peripheral ophtalmometer with variable fixtures demonstrates that the shape of the cornea is elloissoidical.
Westheimer (1961) demonstrates that the application of a contact lens, able to correct the aberrations of the eye, requires a profound knowledge of the cornea.
Bonnet e Cochet (1962) perfection the stereo-photogrammetric method.
Fincham (1961) proposes a modification to the Drysdale technique based on a system of collimation.
Francis (1962) sustains that the shape of the central part of the cornea, of 3 mm, is spherical.
Mandell (1962), theorizes on the reconstruction of the shape of the cornea, strating with data gathered in a number of points, is in favor of the ellipsoide shape.

Stone (1962) examines the limitations and methods that are used correctly to measure the corneal curvature. For example, a string of 7.5 mm is necessary to measure a radius of 7.5 mm with a precision of +1 mm.
Jenkins (1963) discusses the aberrations of the cornea and the entire eye, admitting that they cornea is spherical and considering pupils of various diameters. In particular, he considers the spherical aberration and the “false astigmatism” and considers also the role of the posterior surface of the cornea.
Bennet (1964) proposes a direct measurement of the curvature of the radius of the cornea, using a modified version of the Drysdale method and reduces the number of “readings” simultaneously.
Source Luce e Immagini, by Prof. Sergio Villani and Prof. Luigi Santalucia.
Related article: Brief history of the determination of the cornea’s shape (7/9)

Blue Personality
They love to keep situation under control. They are result minded and think of new opportunities.
They accept new challenges with pleasure, often risky, they establish objectives and work intensely to reach them. Keeping the situation under control is fundamental for the blue personalities. They are often chosen as leaders and hate the rules that are established by others, preferring to give their own mark. From the position of force, the directors see the strategic advantages and coordinate the actions to beat the coompetition. They tend to work hard and intensely. They show a lot of inititiative, are excellent leaders, assertive and direct.

Personalità gialla
They know the important persons. They love to talk with anybody, of anything at any time. Lively, energetic, spontaneous, they love to amuse themselves in anything they do. They are excellent communicators and can be very convincing. The presenters give the impression to be people of success. They love variety, are curious and sometimes impulsive. They don;t want to be tied up with a single thing and lose interest when a project is started up. They attract people with naturality. Creates trusting relations, people confide themselves easily with them. They feel good when they are the center of attention.

Red Personality
They care for people and are liked by everybody. The become experts in their field and are sought after for their suggestions and experties. They are extremely available, sometimes excessively. The mediators have the ability to have everybody feel relaxed. Though loving people they are generally reserved in their style of communication. They hate ostentation and are often considered “flat” as presentors. The mediator leaders instill confidence in their collaborators. Patient, accurate, tollerant, the leaders and their collaborators can move a mountain, a piece at the time.

Green personality
They are precise, accurate, tactical, hard workers. They are expert in the analysis and solutions of problems. They respect the rules and think accirately and slowly, evaluating almost everything and everybody. The strategists hate to make mistakes and to be wrong. Their position is always clear because they are clear and diplomatic communicators. They tend to be perfectionists considering all details. They are very good in the practical/operative application fundamental in each project. They don’t stop until the project is completed.

Related article: Personalità a colori 1/2.
A cura di Francesca Bianchi, fonte b2beyesmagazine del 17 Ottobre 2007

Returning to the determination of the shape of the cornea, Lenoble (1922) photographed the reflected images and thus deduced the position of the meridian line.
In 1953, Dudragne measured on a large scale (10,000 normal eyes and aphacics, that showed a post-surgery astigmatism of 2.5 diopters). He concluded that the cornea is not an elipsoide nor a limbus, and that deviations can also reach the 30 diopters.
Fincham (1953) perfected the photokeratoscope, naming it reflectgraph, succeeding also to photograph a corneal area of 7 mm. Ivanoff (1953) proposed a model of the eye with a spheric cornea around its backward pole.
Lenoble and Salomon (1953) determined the shape of the cornea with a graphical integration of the elements supplied by the images from the incandescent lamps, situated on the arch centered on the cornea, orientable on the various meridians.
Bier (1956) asserted that the optic cap of the cornea extends from 4 to 6 mm and is surrounded by a negative depression..
Meanwhile, contact lenses start to be sold on a large scale. Bier (1956-1957) : the cornea has an optical cap of 4 to 6 mm, a bit decentralized towards the nose and upwards, surrounded by a negative depression that outwards assumes a positive curvature. Furthermore, there is a general flattening of the nasal half.
Nordensen (1956) describes the cornea as a asymmetric catenary while Mandell (1959) describes it as a hyperbole.
Knoll, Stenson e Weeks (1957) improve the disc that is reflected by the cornea and in order to improve the area of the optic cap they use and aperture of f/11, thus producing an increase of depth.
From the examination of a large number of eyes it is concluded that the optic cap can be compared to a sphere. Meanwhile, Sosby, Benjamin e Sheridan (1957) confirm the sphericity on 3 mm of width.
Using the keratometer Bausch e Lomb, May (1957) measured the flattening of the peripheral cornea.
Averaging between the nasal and temple portions, he concluded that the flattening causes a variation of power between 0.18 D at 1,17 mm from the corneal centre, e of 3,5 D at 5.7 mm.
While Bayshire (1959) improves the keratometer, introducing two points of auxiliary fixtures, Bonnet (1959) theorized on the corneal topography obtained with the stereo-photogrammetic and on the interpretation of the stereograms. He sustained that the precision of the determination of the radius of curvature in one point is of 4/1000. The peripheric flattening is described as a linear function of the distance of the pole.
Evershed-Martin (1959) sustains that the peripheric flattening around the optic cap has not yet been demonstrated in a convincing manner (as instead in the case of corneal astigmatism). Moss (1959), instead is in favor of the flattening around the optic cap, in agreement with Bier.
Source Luce e Immagini, by Prof. Sergio Villani and Prof. Luigi Santalucia.
Related article: Brief history of the determination of the cornea’s shape (6/9)

What interests us most is the part of the brain where the cortex is located, subdivided in 4 areas that scientists have marked with 4 different colours. Each individual has all 4 colours but there is one that dominates.
To recognize to which personality we belong, our employees and our customers helps us in finding the right kind of communication to socialize, to coach, to sell and to obtain concrete results. Many like Jung, De La Parra Paz, Pcsi and many more have defined them but why don’t we use them? There is no sales class, team management or communication that does not propose the quadrant test. I am asking myself: why are we so reluctant to modulate our communication that adapts itself best. Are we maybe all convinced that it is not necessary? Whenever I start a sales class, a management class or communication class the first thing that the participants tell me “The customers, employees, managers don’t understand me” and my answer is always: “I would be rich if I could hold this class to all your customers, employees and managers. Send them to this classroom and I’ll explain how they can understand you”. There are no shortcuts, you have to start with yourself. First of all you have to understand which quadrant represents you best, then through questions, reading of body language and other tricks that are taught in this class you can adapt to your speaking partner. Is it difficult? Yes, it is as it was difficult to learn walking, ride a bike, ski, play tennis, drive a car but you didn’t stop learning, right? You can all walk, right? You drive a car. Why should this be more difficult?
There would be an alternative that doesn’t require any effort from you: you go to the customer with a nice test and you let him fill-in the answers. Now you know who he is!
Then you may explain him how you are made so that he can adapt himself to you…. but that is somewhat hard! What to do?
Read, study and participate in communication classes, apply that knowledge and above all convince yourself that communication is not made of intentions but in the feedback. See you in the class room!

Continued in Personalities in Colour (3/3)

By Francesca Bianchi, source b2beyesmagazine of 17 October 2007