HUMPHRISS IMMEDIATE CONTRAST (HIC，一種雙眼同時打開的驗光方式)

     在單眼驗光之後需要進行雙眼調節平衡，方式有很多種，其中一種較特別的方式為HUMPHRISS IMMEDIATE CONTRAST (HIC)。概念是先霧視非檢查眼，接著在檢查眼之前輪流以+/-0.25DS鏡片比較清晰度。

    此種方式的好處是兩眼皆處於開放狀態，有雙眼融像更接近真實視覺狀態，調節也能有較好控制。

    當比較兩片鏡片時。會有三種可能的結果，+0.25DS比較清楚、-0.25DS比較清楚、兩者相同。    

    但不同教科書上對於步驟及終點卻有不同的描述，又因為最原始的版本無法獲得，所以我試著比較手上三本有比較完整步驟的教科書，看看不同作者的作法。

1. Clinical Procedures for Ocular Examination 4th

/NANCY B. CARLSON,  DANIEL KURTZ

這本是大部分視光學校的屈光實驗教科書，書上對於終點是這麼描述的

• a. If the patient reports that the -0.25 D sphere is clearer, add-0.25 D to the correction (or take away + 0.25 D) and continue step 5 until the two views appear equal.
• b. If the +0.25 is preferred, add a +0.25 to the correction and continue step 5.
• If on the next comparison the patient prefers the -0.25, add the -0.25 and proceed to step 6.
• c. If the two views appear equal, leave the correction as is and proceed to step 6

...終點為直到兩片鏡片看起來相同．而正或負清楚則加入相對應鏡片之後到反向出現．

2. OPTOMETRY : Science, Techniques and Clinical Management

/Mark Rosenfield, Nicola Logan

• lf the patient is not accommodating, then they should immediately respond that the target is clearer with the minus lens.
• lf the patient gives one of three responses , either that
• (1) the plus lens is clearer
• (2) that there is no difference between the two lenses or
• (3) that the minus lens is clearer, but it makes the letters smaller or blacker,
• then it can be assumed that the patient is accommodating.
• With any of these three answers, additional plus sphere should be added and the test repeated until the patient has no hesitation in responding that the-0.25 DS is preferred.

...終點為負鏡片清楚．兩者相同或正鏡片清楚或負鏡片影像縮小則繼續加正鏡片

3. Clinical Procedures in Primary Eye Care

/David B. Elliott

• 6. If the patient immediately reports that the-0.25 DS is definitely clearer, repeat the demonstration of the lenses and ask if the-0.25 DS ‘is definitely clearer or just smaller and blacker’.
• Only add -0.25 DS if the patient immediately reports that the lens is definitely clearer.
• 8 .If the patient reports that the +0.25 DS is clearer or that there is no difference, add +0.25 DS to the refractive correction
• 10.Continue to compare the -0.25 DS and +0.25 DS until the +0.25 DS is immediately rejected.

...終點為正鏡片被立即拒絕．正鏡片清楚或兩者相同繼續加正鏡片