March 18th, 2014

SCO Visit  Joseph Hauser from SCO will be visiting our Club! Visit will occur Thursday, April 10 th (4/10/14) at 8:00 PM Will take place in the Shenandoah Conference Room (Room 314)  Wytheville Optometrist and SCO/Virginia Tech Grad Dr. Houston Teaters will also be visiting

In The News 

Color Blindness  Technically recognized as a form of “Color Vision Deficiency” by the AOA  Many forms of color deficiency, with the most common being red-green colorblindness  Can be innate (congenital) or acquired (less common)

Understanding Color Blindness: Physiology  Cone Cells Retinal photoreceptor cells distributed throughout the retina, fovea is almost exclusively cones Bipolar Cells – Receive stimuli from one end and transmit to the optic nerve 3 subtypes for each color range: ○ Short (S) – detect purples, blues, and greens ○ Medium (M) – detect many colors, from greens to yellows, to reds ○ Long (L) – detect greens, yellows and reds

Types of Color Blindness  Dichromacy Red/Green Color Blindness (Protanopia/Deuteronapia) ○ Less sensitive to red light (Protanapia) Affects the L-Cone ○ Less sensitive to green light (Deutrtonapia) Affects the M-Cone Yellow/Blue Color Blindness (Tritanopia) ○ Confuse blues for greys, greens for blues, and oranges with reds ○ Affects the S-Cone

Red/Green Color Blindness

Yellow/Blue Color Blindness (Tritanopia)

Video  r r

Other color vision deficiencies  Anomolous Trichromacy – These individuals can see many colors. All of their three cone types are used to perceive light colors but one type of cone perceives light slightly out of alignment, caused by a faulty cone subset.  Ex. Protanomaly, Deuteranomaly, Tritanomaly

Deuteranomaly

Other color vision deficiencies  Achromatopsia – These individuals see in grayscale; a type of monochromacy. Contain no cones.

Summary

Hereditary Basis of select color vision deficiencies  Inherited color blindness is from a mutated gene on the X chromosome  Males only have 1 X chromosome, while females have 2. The female’s second X chromosome takes precedence over the mutated one  Males are 20X more likely to be colorblind than females

Hereditary Basis of select color vision deficiencies

Color blindness across ethnicities MalesFemales Caucasian: 6-8%Caucasian: <1% Asian: 4-5%Asian: <1% African American: 3-4%African American <1%

Causes of Acquired Color Vision Deficiency  Disease  Medications  Physical Damage  Chemicals  Aging

Diagnosis  Commonly tested for in a comprehensive eye exam  Use of pseudoisochromatic plates (PIP)

Examples

Treatment  There is no true cure for inherited color deficiency  If colorblindness is linked to injury, treating the underlying damage may alleviate symptoms  Often, people will adapt techniques to cope, such as organizing/labeling colored objects, or mentally categorizing like colors

OAT Practice Problem  The relative diameters of the blood vessels of the body and the relative flows are as listed: Arteries > arterioles > capillaries  In which of the above is turbulent flow more likely? A. artery B. arteriole C. capillary D. All equal

OAT Practice Problem  The relative diameters of the blood vessels of the body and the relative flows are as listed: Arteries > arterioles > capillaries  In which of the above is turbulent flow more likely? A. artery

OAT Practice Problem  Melatonin is produced by the: A. Pineal Gland B. Skin C. Liver D. Pituitary Gland E. None of the above

OAT Practice Problem  Melatonin is produced by the: A. Pineal Gland

Pre-Optometry Officer Elections  Requirements: Paid Member Attend at least 50% of all meetings  Format: Speeches Cascading ballot Please me if you are considering running for a

Pre-Optometry Officer Elections  President: Leads meetings Books rooms Requests speakers  Vice President: Assists President with tasks Updates Facebook page and/or website

Pre-Optometry Officer Elections  Secretary: Records and s minutes of each meeting. Manages Listserv  Treasurer: Attends the Budget Board Meeting Manages Bank account and membership fees

Thanks for coming!  Next meeting will be on April 1st, :30 pm in the Squires Mountain Lake Conference Room  We will hold elections next meeting!  Questions?