Page 39 - SSB MED EBOOK

(a) Convergence

(i) Objective Convergence. Average is from 6.5 to 8 cm. It is poor

at 10 cm and above.

(ii) Subjective Convergence (SC). This indicates the end point of

binocular vision under the stress of convergence. If the subjective

convergence is more than 10 cm beyond the limit of objective

convergence, the fusion capacity is poor. This is specially so when

the objective convergence is 10 cm and above.

(b) Accommodation. In the case of myopes accommodation should

be assessed with correcting glasses in position. The acceptable

values for accommodation in various age groups are given in Table

1.

Table 1. Accommodation Values - Age wise.

Age in years 17-20 21-25 26-30 31-35 36-40

41-45

Accommodation 10-11 11-12 12.5-13.5 14-16 16-18.5

18.5-27

in cm.

Ocular muscle balance is dynamic and varies with concentration,

anxiety, fatigue, hypoxia, drugs and alcohol. The above tests should

be considered together for the final assessment. For example,

cases just beyond the maximum limits of the Maddox Rod test, but

who show a good binocular response, a good objective

convergence with little difference from subjective convergence,

and full and rapid recovery on the cover tests may be accepted. On

the other hand, cases well within Maddox Rod test limits, but who

show little or no fusion capacity, incomplete or no recovery on the