Amplitude Of Accommodation Inspection

Accommodation: the process in which the human eye changes the curvature of the lens to increase the refractive power of the eye so that close objects can still be clearly imaged on the retina, which is called eye accommodation.

Before Accommodation 

After Accommodation 

Amplitude of accommodation (AMP): the maximum accommodation force that the human eye can produce is called accommodation amplitude, which is the difference between the refractive power when looking at the far point and the near point.

Inspection Method

1.Push-Up
2.Minus Lens
3.Hostetter
4.Donder

1.Push-Up

It stimulates the accommodation of human eyes by gradually moving the index closer to the divergence of light. It is a subjective method to measure the amplitude of accommodation.

Operation Steps:

1. Correct the ametropia of the tested eye.
2. Cover the left eye and measure the accommodation amplitude of the right eye.
3. Place the vision chart at 40cm from eye,which is above the row of chart with best vision on near vision card,and ask the patient to look at the vision chart with the tested eye.
4. Move the near vision card to the measured eye at the speed of 1cm / s,until the vision chart is continuously blurred.
5.Record the distance from the near vision card to the main point of eye and convert it into the accommodation amplitude.If the distance from the vision card to the main point of eye is 10cm,accommodation amplitude = 1 / 0.1 = 1.0 (D)
6. Cover the right eye and test the left eye according to the above steps.
7. Open both eyes and test both eyes according to the above steps.

2.Minus Lens

It is a method to measure the amplitude of accommodation by adding minus lenses in front of eyes to stimulate the generation of accommodation.

Operation Steps:
1. Correct the ametropia of the tested eye.
2. Cover the left eye and measure the accommodation amplitude of the right eye.
3. Place the vision chart at 40cm from eye,which is above the row of chart with best vision on near vision card,and ask the patient to look at the vision chart with the tested eye.
4.Slowly increase the minus lens (with an interval of 5 ~ 10 seconds) with -0.25D as the first gear in front of the patient until the visual chart is continuously blurred.
5. Record the increased minus lens degree, and the accommodation amplitude is the absolute value of the increased minus lens degree plus 2.5D (the accommodation force generated by the near visual chart at 40cm).
6. Cover the right eye and test the left eye according to the above steps.
7. Open both eyes and test both eyes according to the above steps.

We'll share two other methods next time!