The Development Of The Eye During Embryonic Development

Most individuals take for granted their ability to see. Eyesight is a major connection to the outside world; around 80 percent of impressions are through sight, meaning that only 20 percent are from the other four senses. The human eye has evolved over time to turn into what it is today. Through human’s needs for survival, the eye has changed to suit humans. Two of the most common types of eyes found in nature are the camera-type eye and compound eyes; the human eye fits into camera-type eyes because just like a camera lens focuses light onto something, the eye does a similar thing. The cornea, a structure in the front of the eye, focuses light onto the retina, and behind the cornea, is a colored membrane called the iris. It has an adjustable circular opening, the pupil, which expands or contracts to determine the amount of light that enters the eye.

INTRODUCTION. Idiopathic congenital nystagmus, or idiopathic infantile nystagmus is a disease characterized by the rapid, involuntary eye movement. This movement is typically in the horizontal direction, however, movement in other directions have been observed. One way to get nystagmus is through genetic mutations. Nystagmus caused by genetic mutation is seen at a relatively young age but cannot yet be treated. The disease is not understood well, it is believed that the cause is a developmental defect. The linkage, and inheritance has not been identified, the patterns suggest that multiple genes are involved in the disease and that there are loci on different chromosomes with three of the five loci located on the X chromosome. Mutations have been linked to the FRMD7 gene, a gene that consists of 12 exons, of the FERM family. The function of FRMD7 have yet to be determined however an abundance of the protein in the brain in areas associated with the eye. Mutations within this region consist of missense, deletion, tranversion and nonsense mutations. Over forty-four mutations that lead to ICN have been found in the FRMD7 gene. Learning more about the mutation of FRMD7 in ICN is important because these mutations may prevent elongation of neurite processes during differentiation preventing axons from responding to stimuli (Watkins et al. 2012).

1. These enzymes are used by the sperm to create an opening in the corona radiata, zona pellucida, and plasma membrane of the oocyte for the sperm to pass through

Eye Vision Inc, a long-standing medical device manufacturer, has signed a contract to sell Holland Hospital the Clear View Laser and a two-year separately priced maintenance plan for $1 million and $0.2 million respectively. On a when-and-if available bais, Eye Vision Inc. will provide software updats that is embedded with the Laser to maintainance purchasor. The software has never been sold without Laser for its functional necessity. In this memo, as explained below, we conclude that:

Since AAV2 vectors do not eliminate or repair the faulty gene, the therapeutic effects may not be permanent. In several studies, improvement of visual sensitive peaked a few

Color Vision Development in Infants: The Responsibility of Cone Types and Wavelength in Order of Color Development

The process of myelination is pivotal in the development of young children. The myelin is a fatty coating surrounding the axon that increases transmission between neurons. Before the age of six they are maturing and developing faster whereas, under six the child may forget what they are doing before they finish the task at hand. At six years old the most children can see an object and identify it, catch and throw a ball, and write their ABC sequences without default. Information is still processing slowly at six years of age (Berger, 2011).

Aniridia is caused by the Pax6 gene. This gene is responsible for eye development and when it doesn't function correctly the eye stops developing too early and this causes the baby to be born with underdeveloped eyes. Eyes that are affected by Aniridia look like the pupil is extremely large and the color of the eye can barely be seen. In rare cases the color of the eye (the iris) can't be seen at all.

While aniridia remains the predominant phenotype associated with PAX6 mutations, congenital cataract (Azuma et al., 1999; Bremond-Gignac et al., 2010), was also shown to be associated with PAX6 deficiency. PAX6 mutations which are associated with aniridia and congenital cataract have been reported in the Human PAX6 Allelic Variant Database (http://www.hgu.mrc.ac.uk/Softdata/PAX6/). Cataracts are the leading cause of blindness within the United States and are expected to rapidly increase in incidence with an aging population. Military personnel are not exception to the incidence of this disease. Congenital cataracts are visually devastating and considered disqualifying in AR 40-501 Standards of Medical Fitness. An understanding of the pathogenesis

This paper considers that focused primarily on human iris. This choice of this topic was made due to interest of wanting to provide knowledge about the factors that determine eye color. I know, like hair or skin, brown eyes are dominant over blue eye genes. I also know that a person can be identified by the retina scanners because everyone has their iris with unique structural patterns.

Eye development is initiated by the master control gene Pax-6, a homeobox gene known as Andridia in humans, small eye in mouse, and eyeless in Drosophila. The Pax-6 gene locus is a transcription factor for the various genes and growth factors involved in eye formation. Eye morphogenesis begins with the evagination, or outgrowth, of the optic grooves or sulci. These two grooves in the neural folds transform into optic vesicles with the closure of the neural tube. The optic vesicles then develop into the optic cup with the inner layer forming the retina

It is easy to see that there is some differences from one person to the next. These differences can be hair color, eye color, skin color, facial structure, eye structure, etc. These different characteristics are polygenetic traits: hair color, eye color and skin color. Polygenetic trait is multiple genes mixing with each other to create the characteristics like blue eyes. The eye color is controlled through the genes from both parents that are passed through to their child. Scientist have found that there is multiple genes that decide what color the eye needs to be or will be. The color of the eye is often slightly or way different from one person to the next. The color of the eye has the function of controlling how much light enters the eye.

monitor fetal heartbeat. In the first stage of labor , the neck of the uterus,

Brain development in the first two years is the most important and critical. Maria Montessori referred to this time as of the "absorbent mind" Early brain development is the frame work for the road ahead. When and how the brain develops in the first two years will play a critical role into adulthood. At birth, the brain is the only incomplete organ. The brain will continue to grow through childhood and adolescents.

Light, a concept that has been worked with for many years dating back to 500 B.C. Pythagoras hypothesized that humans perceive light due to the human eyes ability to emit rays upon the environment and the emittance gives a human his or her sight (Sekuler). Afterward, human intellectuals started making it more concise to present day knowledge of light. This development of light came from two intellectuals named Christian Huygens and Isaac Newton. Newton exclaimed during the 1700s that light was a stream of particles carrying energy but Huygens, Newton’s contemporary, thought that light needed this invisible “ether” in order for these streams to make light travel. Then, a couple hundred years later, modern scientists such as Albert Einstein, Thomas Young, and Augustin Fresnel proved Isaac’s and Huygens’ hypotheses of light (Rossing, 23-24). This is how the basis of light was created.