1. The eye is an organ that can sense light. The simplest eye structure can detect the light and shade of the surrounding environment, and the more complex eye structure can provide vision. In many vertebrates and some mollusks, the eyes image by projecting light onto the light sensitive retina, where light is received and converted into signals that pass through the optic nerve to the brain
make the divergent light from the near object bend and image on the retina, then the near object can be seen clearly, which is called regulation. The distant point of emmetropia is more than 5 meters, and the distant point of myopia is less than 5 meters. The formula of D = 1 / F (diopter = 1 meter / focal length) can be used to calculate the distant point of myopia, that is, the distance that myopia can see the target. For example, the distance that 4.00d myopia can see the target is 0.25 meters
extended data
in the process of eye adjustment, abnormal adjustment occasionally occurs, the main reasons are as follows:
1, insufficient adjustment, accompanied by exophora, mostly caused by long-time close work
2. Hyperadjustment was more common in children. When looking at close objects, the regulatory response was greater than the regulatory stimulus
However, the response was slow when the distance and distance were alternately fixed
2. The required accommodative force = Original ametropia + 33cm accommodative stimulus, 1. The required accommodative force = + 2.00d + (+ 3.00d) = + 5.00d; 2. Required adjusting force = - 1.00d + (+ 3.00d) = + 2.00d
3. Accommodation is not determined by hyperopia or myopia. Regulatory power is age-related, but there are also some differences among indivials. There are two ways to get the adjustment force. One is the calculation method: 15-0.25 * age = adjustment force. The second is the comprehensive optometry test: after the full correction of 40cm, put on glasses, look at the best visual acuity line, add concave lens in front of eyes, until the visual target is blurred, the increased value is the adjustment force. I hope I can help you.
4. There is no subway to get there. Besides, you have to change buses. Take airport line 6 (35 stops) to get off at the east overseas Chinese town (Dameisha) station, cross the road, go right to another east overseas Chinese town (Dameisha) station, and then take m362 (formerly 364 stops) to get off at Rose coast station. Go back about 70 meters to rose coast
5. 1. Walk about 180 meters from Xixiang bus station (Bao'an Avenue) to Xixiang bus station (Bao'an Avenue), take No. 338 (29 stops) to Union Square Station, and then take No. m362 (original No. 364 stops) (31 stops) to rose coast station. Go back about 70 meters to rose coast. 2. Take a taxi for 55.8 kilometers. Green Taxi: the cost is about 179 yuan. 3. Walk about 770 meters from Xixiang bus station (Bao'an Avenue) to exit b of Xixiang station, take Luobao line (line 1) (station 24) to Laojie station, then take Longgang line (line 3) (station 20) to exit a of Shuanglong station, Go ahead to Shuanglong subway station (bus stop) and take bus No.818 to Kui Chung Street office station. Then take bus no.823 to rose coast station. Walk about 110 meters to rose coast 4. Walk about 770 meters from Xixiang bus station (Bao'an Avenue) to exit b of Xixiang station, take subway Luobao line (line 1) (take 15 stops) to entrance C of Zhuzilin station, go to Futian hub terminus (bus terminus) and transfer to m362 (original 364) (take 44 stops) to rose coast station. Go back about 70 meters to rose coast 5. Walk 180 meters from Xixiang bus station (Bao'an Avenue) to Xixiang bus station (Bao'an Avenue), take bus No. 367 (to Huanggang) (take 20 stops) to Tian'an digital city station, and then take bus No. m362 (original No. 364) (take 41 stops) to rose coast station. Go back about 70 meters to rose coast
6. Line 1 to line 2, under the instrial exhibition hall, exit b, go north along Qingnian Street, turn right on Wenyi Road, and then turn right on Jianyuan street
7. You download a software Longdi engine, which has the information of trains, buses, flights and hotels all over the country. You can directly input your departure place, such as Tiananmen Square, and write Sanyuanqiao at the end. After you choose Beijing, you can see where you are going and where you are going. In fact, the easiest way is to find a taxi and say go to Sanyuanqiao quickly!
8. Shenyang Jiali Center
9. Unknown_Error
10. Hyperopia refers to a refractive state in which the parallel light beam is refracted and imaged behind the retina. Hyperopia occurs when the refractive power of the eyeball is insufficient or the axial length of the eyeball is insufficient. The optical focus of this eye is behind the retina, so the image formed on the retina is blurred. In order to see the near object clearly, we should use the adjusting force to move the focus behind the retina to the retina, and generally use convex lens to correct it. Therefore, the hyperopia is often in the adjusting state, which is prone to eye fatigue.
