Understanding Color Blindness

Understanding Color Blindness

Article written by Paulus Maciel. Rights reserved.

The goal of this matter is to facilitate the understanding of the professional optical about color blindness and how to provide the best comfort and that individual perception through ophthalmic lenses. blindness, also known as dyschromatopsia, is characterized by atypical visual perception that can not distinguish two different colors, In most cases green and red.

Figure 1

The term "color blindness" comes from the name of the British scientist John Dalton (1766-1844) who was the first to study in depth the theme, motivated precisely because he is a person with dicromatopsia.

Fig 2

Before Dalton, many thought that the blindness was an issue related to the eyes and now know that it is a genetic abnormality of the X chromosome that leads to difficulty of the perception of some primary colors. Perception of this character neurological and ophthalmological not. See the images at hand, as is normal vision (Fig. 1) and the vision of a person with color blindness.Note that there is the difficulty of differentiating the colors green and red.Due to this distinctive visual perception, the colorblind can have excellent night vision and can easily distinguish people or objects partially hidden in the environment. Colorblindness is more common in men than in women by men just possess only the X chromosome while women have both X and Y. An estimated 8% of the male population and only 1% of the female is colorblind. Sometimes color blindness is not manifested in women, but it can be a carrier of the gene. Blindness What can be hereditary, depending on the combination of parent versus parent regarding the manifestation in the mother / father or mother in the presence of the gene as follows:

• If the mother is not colorblind nor a carrier (DD) and father have normal vision (D) none of the offspring will be colorblind nor a carrier.
• If the mother has normal vision (DD) and the father is colorblind (d) none of the offspring will be colorblind, but the daughters will be carriers of the gene (Dd).
• If the mother is a carrier of the gene (Dd) and father have normal vision (D), there is a 50% probability of being colorblind children and 50% of daughters are carriers of the gene.
• If the mother is a carrier of the gene (Dd) and the father is colorblind (d), 50% of sons and daughters will be colorblind.
• If the mother is colorblind (dd) and father have normal vision (D), all children will be color blind (d) and all daughters will be carriers (Dd).
• If the mother is colorblind (dd) and father also (d) 100% of sons and daughters will also be colorblind.

There are several methods for the diagnosis of color blindness, the best known of them is the Ishihara test, where the examinee that has some sort of color blindness can not see letters, numbers or shapes applied in a mosaic. See an example below. If you want to take a test online, click HERE.

What number is within the mosaic?

For more colorblind accessibility to information such as traffic lights, traffic signs, maps etc, the Portuguese designer Miguel Neiva created the Color ADD, a very efficient system of identifying colors for colorblind, see an example below.

 

For more information on the Color System ADD, go to http://www.coloradd.net/index.aspor visit the fanpage of Color ADD on Facebook by clicking HERE . Regarding the day-to-day professional scanning, Carl Zeiss Vision has medicinal filters that are applied to eyeglass lenses. Each filter has a function for each type of color blindness. From now on, we know these filters and their applications.

• F540, F560 and F580 filters are ideal for monochrome, low vision, nistagma and poor discrimination of colors, eg green and red.

 Below is a sampling of the filter F540:

 Below is a sampling of the filter F560:

Below is a sampling of the filter F580:

 

• The filters F452 and F451 are for monochrome and Achromatopsia Blue Cone.See examples in the illustration below.
  
  
   
  Below is a sampling of the filter F451:
  
  
  
  
  
  
  Below is a sampling of the filter F452:
  
  
  
  
  
  
  The filters are applied medicinal Zeiss lenses exclusively on Zeiss 1.5 both in single vision as progressive in the modern Zeiss Technology Center in Petropolis.
  
  Despite the blindness be, nowadays, considered irreversible, there are excellent products that can provide greater comfort to the user, improving their visual perception.