Will eye surgeons remove cataracts from both eyes even if one is a partially-blind lazy eye with 20/400 vision?

Sometimes, but obviously nobody should expect the best possible visual acuity in the "lazy eye."

It depends on several things about a particular patient's situation. In this case, the person is essentially a one-eyed patient. It would not be surprising that (s)he would probably put off as long as possible seeing an eye doctor where surgery might be a possibility. If the "good eye" is now severely compromised from cataract, it might help the patient's confidence and allay the fear of going blind by doing cataract/lens implant surgery in the "bad eye" first. This would also allow the surgeon to find out first hand if there might be any unsuspected challenges since the two eyes generally respond quite similarly to cataract surgery. Furthermore, improvement in visual function from cataract surgery is not strictly a matter of seeing more lines on the eye chart -the overall increase in contrast sensitivity, decreased refractive error, and wider visual field are often greatly appreciated by patients like this despite only seeing the 20/400 line.

None of these reasons mean the patient has to have the "bad eye" operated on, though. But amblyopia ("lazy eye") is not an absolute contraindication to cataract surgery.

_Written by J. Trevor Woodhams, M.D. - Chief of Surgery, Woodhams Eye Clinic