To review:
The cause of blindness of premature babies who were born before 25 weeks after conception.
Introduction:
The outermost covering of the eye is known as sclera and the cornea. The cornea forms a dome-shaped structure at the front side of the eye. The inner layer of the eye is the retina that includes rod and cone photoreceptor cells. These cells provide vision at different intensities of light. Various types of disorders are associated with vision and some of them are related to age while others are related to other reasons. Some of the common disorders that are associated with visualization are cataract, glaucoma, and some other conditions that are associated with accommodation.
Want to see the full answer?
Check out a sample textbook solutionChapter 16 Solutions
Human Anatomy Laboratory Manual With Cat Dissections (9th Edition)
- Grandpa can't ever seem to hear what his little granddaughters say. He also can't hear that high-pitched whine in the Subaru engine that everyone else seems to hear. You suspect that grandpa has too much ear wax built up in his external auditory canal, and therefore has developed conduction deafness has damage to the vestibulocochlear nerve has damaged either the utricle or the saccule, though it will be hard to tell which one without further testing has damaged the hair cells closest to the oval window has "selective" hearing loss, because the granddaughters are always trying to get him to play with them when he's tired, and he doesn't want to work on that darned car anymore either.arrow_forward1) Those with blindsight think they can't see but can react to visual stimuli anyway. Why? they are faking being blind: they can see just fine, just like us the part of the cortex that controls conscious vision is still intact because the part of their visual system that controls visual reflexes is still intact because their eyes work fine and they also don't actually have any brain damage 2) Those with blindsight think they can't see but can react to visual stimuli anyway. Why? they are faking being blind: they can see just fine, just like us the part of the cortex that controls conscious vision is still intact because the part of their visual system that controls visual reflexes is still intact because their eyes work fine and they also don't actually have any brain damagearrow_forwardGeorge was under a lot of stress. His final semester examination was only 2 days away, and he was not prepared at all. To make matters worse, his right eyelid suddenly started twitching, and he couldn’t concentrate. Should George be worried about his eye? What is the reason behind this twitching?arrow_forward
- What is one of the many benefits of having both direct and periphery vision at your disposal? A) It serves to entertain us by making optical illusions fun. B) There is no real survival benefit to having direct and periphery vision. C) There is a survival benefit where periphery vision catches sudden movements and direct vision depicts greater detail. D) Having periphery vision is the reason why we see colors, which have survival benefits.arrow_forward(Bonus) Deafness and hearing loss are a widespread issue. According to WHO, currently more than 1.5 billion people (nearly 20% of the global population) live with hearing loss. From what you learned about our auditory system, briefly explain what would happen to hearing in each of the following scenarios. (a) the tectorial membrane can't hold its position and is pushing onto the auditory hair cells constantly. (b) the auditory hair cells near the base of the cochlea are damaged and dead. (c) the endolymph potassium concentration is lower than normal. (d) the perilymph potassium concentration is lower than normal.arrow_forwardThree patients have suffered destruction of different portions of their visual pathway. Patient 1 has lost the right optic tract, patient 2 has lost the nerve fibers that cross at the optic chiasm, and patient 3 has lost the left occipital lobe. Draw a picture of what each person would perceive through each eye when looking at a white wall.arrow_forward
- Why does your near point of vision move farther away as you age?arrow_forwardA Physician Assistant student on clinical attachment in the Northern part of Ghana noted a high incidence of people reporting difficulty with night vision which has been due to lack of vitamin A in their diet. Explain why deficiency of vitamin A causes poor night vision or night blindness.arrow_forwardWhy should children with hearing aids utilize FM technology?arrow_forward
- a 5 year old boy is diagnosed with color blindness , this boy most likely has an abnormally in which of the following ?. A) cones, B) lateral geniculate nucleus of the thalamus . C) lens, D) optic nerve, E) Rodsarrow_forward4a) Which of the following is true about infants’ visual acuity? Select one: i. Poor visual acuity early in life allows key features of the visual world to “pop out” ii. Before 3 months, infants are not able to make sense of their visual world iii. It’s not possible to test visual acuity before infants are 6 months iv. Newborns have poor visual acuity, but excellent colour vision 4b)You see the results of an eye-tracking study in which infants were required to look at human faces. You see that infant A spent most time looking at the contour of the face, while infant B spent a lot of time looking at the eyes and the mouth. You conclude that infant B is most likely: Select one: i. Showing signs of a developmental disorder ii. Older than infant A iii. Bilingual iv. Younger than infant A 4c)Which statement is FALSE regarding infants’ perception abilities at birth? Select one: i. Even young babies have visual biases that help them organize their visual world (e.g., use of motion cues) ii.…arrow_forwardWhich statement about the events of photoreception is false? a) as a rod cell hyperpolarizes, its release of neurotransmitter increases b) there is more Na+ entry into a rod cell in the dark than in the light c) bipolar cells release more neurotransmitter in the light than in the dark d) as a bipolar cell depolarizes, its release of neurotransmitter increases e) when a rod cell releases neurotransmitter the bipolar cell it synapses with hyperpolarizesarrow_forward
- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning