In a video lesson regcarding the topic, it was mentioned that an eye that undergoes an operation of cataract, loses its ability to adjust its focal length. If this is so then what is the difference between such an eye an a presbyopic eye? Please explain.

Asked by aarti prakash | 14th Mar, 2011, 03:45: AM

Expert Answer:

Dear student,
 

Presbyopic eye acts like a "fixed-focus" camera, which means that it'll see well only at a particular distance. If your distance vision is normal, for example, all you need is over-the-counter reading glasses.

If you correct near vision you'll see clearly up-close, but you can't see distance object clearly with the correction and vice versa. Correcting reading vision is always at the expense of distance vision and vice versa.

When an eye loses its ability to adjust a focal length post cataract operation, The doctor has to check for the quality of the capsule that holds the lens inside the eye. Usually, the cloudiness may form on the capsule too, which may seem as though the cataract has not gone, and the fixing of focal length may be difficult.
 
Hope this helps.
'Thankyou
Team
Topperlearning.com
 

Answered by  | 14th Mar, 2011, 10:50: AM

Queries asked on Sunday & after 7pm from Monday to Saturday will be answered after 12pm the next working day.