Sensitivity to light(medical terms photophobia
) could be because of
- any abrasion/ dust particle / ulcer in cornea(the transparent part of the eye)
- uveitis( inflammation of inner parts of the eye), which is painful too
Both the conditions causes the blood vessels in the white part of the eye( conjunctiva
) to swell up causing redness
So don't ignore it(being already a week's duration) get him examined at the earliest to confirm the diagnosis and start on the treatment. Do not use OTC eyedrops before consultation.
Hope he gets better soon.