|
Tears are made up many substances and they are secreted from various parts of the lacrimal system. The conditions collectively referred to as "dry eye" can occur for many reasons, the most obvious reason being insufficient quantity of tears. An aqueous deficiency refers specifically to inadequate production by the lacrimal glands of the watery part of the tears.
In laser eye surgery, and especially LASIK, aqueous deficiency is basically guaranteed to happen in the short term and may continue for the long term. (This is why consent forms say that dry eye is the most frequent complication of laser eye surgery.) The reason for this is that it is the nerves in the cornea that tell the brain when to tell the lacrimal glands to make more tears. If, as is the case with LASIK, some of the nerves are sliced through and others are vaporised, they are no longer able to detect and transmit the need for more tears. |
