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Adequate stimulus
适宜刺激
The stimulus that a receptor is specialized to receive and transduce. In the case of the eye, the adequate stimulus would be visible light, in the ear it would be sound waves, and so on.
Astigmatism
散光
Astigmatism is a refractive error of the eye that causes the visual image in plane to focus at a different distance from that of the plane at right angels.
Auditory threshold
听阈
The sensation of sound detected by the ear is caused by variation on air pressure within a specific range of frequencies and intensities. The auditory threshold varies with the stimulus frequency and is least over the range 1~3kHz.
Binocular vision
双眼视觉
The impulses set up in the two retinae by light rays from an object are fused at the cortical level into a single image, which is called binocular vision.
Blind point
盲点
In the visual field of each eye, there is a physiological scotoma-the blind point, which coincides with the place where the optic nerve passes out of the eye through the sclera and there is no retina.
Color vision
色觉
Color is a perception. The three cone types have broad sensitivity curves with much overlap, and the sensation of color depends on the extent to which each is excited.
Cone
视锥细胞
Cones are for color and day vision, whose photoreceptors contains three color pigments (red, green and blue sensitive opsins).
Convergence reflex
会聚反射
When the eyes fixate on a nearby object, the signals that cause accommodation of the lens and those that cause convergence of the two eyes cause a mild degree of papillary constriction at the same time. This reflex is called convergence reflex.
Dark adaptation
暗适应
On going from a light environment into a darker one, there is a gradual increase in sensitivity allowing dimmer lights to be seen, a mechanism known as dark adaptation.
Diopter
屈光度
The refractive power is measured in terms of diopter. The refractive power in diopters of a convex lens is equal to 1 meter divided by its focal length.
Hyperopia
远视
In some individuals, the eyeball is shorter than normal and the paralled rays of light are brought to focus behind the retina. This abnormality is called hyperopia or far sightedness.
Light adaptation
明适应
When one passes suddenly from a dim to a brightly lighted enviroment, the light seems intensely and even uncomfortably bright until the eyes adapt to the increased illumination and the visual threshold rise.
Myopia
近视
The axis of the eye is too long, and even with full relaxation, images of objects at infinity are focused in front of the retina. This abnormality is called myopia.
Nystagmus
眼震颤
Nystagmus is an involuntary and abnormally oscillatory movements of the eyes.
Papillary light reflex
瞳孔对光反射
When light is shone into the eyes the pupils constrict, this reflex is called papillary light reflex.
Receptor
感受器
A cell or part of a cell specialized and normally functioning to convert (transduce) environmental stiumuli into nerve impulses of some active response in nerve cells.
Reduced eye
简化眼
If all the refractive surfaces of the eye are algebraically added together and then considered to be one single lens, the optics of the normal eye may be simplified and represented schematically as a "reduced eye".
Refraction
折射
The bending of light rays at an angulated interface is known as refraction.
Rhodopsin
视紫红质
Visual purple; a pigment in rod cells that undergoes a photochemical dissociation in responses to light and, in so doing, stimulates electrical activity in the photoreceptors.
Sensory coding
感觉编码
The receptors not only transform the energy to another kind of energy, but also transform the information from the environment into a train of nerve impulse. This process is called sensory coding.
Transduction
换能作用
The sensory receptors can transforms or transduces a particular kind of stimulus into a change in membrane potential.
Vision
视觉
Vision is the process in which the brain uses information from light-sensitive receptors in the retina to create a representation of the external world.
Visual acuity
视敏度
Visual acuity is defined as the ratio of the distance of the individual from the chart to the distance at which the details of the correctly read line subtend 1'of arc.
Visual field
视野
The field of vision is the area seen by an eye at a given instant. The area seen to nasal side is called the nasal field of vision, and the area seen to lateral side is called the temporal field of vision.
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