Given your mother's age, it is possible that she is suffering from cataract
. This is a condition in which the lens
becomes hazy and this causes problems in This can lead to photophobia
(excessive sensitivity to light). Further, these symptoms are not due to dry light.
A detailed examination by an ophthalmologist after dilating the pupil is required. The treatment for cataract is a small surgery in which the lens is replaced with an artificial lens.
Other possible causes include acute iritis
(inflammation inside eye), corneal abrasion or ulcer and several drugs. This can also be distinguished by an examination.
Taking frequent breaks ( looking away at something 20 feet away every 20 minutes) will also help.
Hope this helps.