Definitions (UK Criteria)

Sight Impairment (Partially Sighted)

•    Best corrected visual acuity worse than 6/18 but better than or equal to 3/60 in the better eye.

•    Or marked visual field reduction, even if central acuity is better than 3/60 (e.g., advanced glaucoma).

Severe Sight Impairment (Blindness)

•    Best corrected visual acuity worse than 3/60 in the better eye.

•    Or visual acuity better than 3/60 but with severe visual field constriction (e.g., tunnel vision less than 10°), making functional vision extremely poor.

Certification Process

•    Ophthalmologist-led assessment and decision.

•    Completion of Certificate of Vision Impairment (CVI).

•    Shared with patient, GP, and local authority.

Support and Benefits

•    Registration enables access to social care services, rehabilitation, mobility training.

•    Financial benefits:

o    Disability Living Allowance (DLA) or Personal Independence Payment (PIP).

o    Blind person’s personal income tax allowance.

o    Travel concessions (free or discounted travel passes).

Low Vision Aids

•    Magnifiers

•    High-contrast and large-print materials

•    Electronic reading aids

•    Enhanced lighting recommendations

Common Causes of Visual Impairment

•    Age-related macular degeneration (ARMD) — most common in elderly

•    Glaucoma

•    Diabetic retinopathy

•    Cataract

•    Inherited retinal dystrophies (e.g., retinitis pigmentosa)

Extra Revision Pearls

•    <6/18 clue → eligible for sight impairment certification

•    <3/60 clue → severe sight impairment (blindness)

•    Severe field loss clue → may qualify as blind even if acuity better than 3/60

•    ARMD clue → most common cause of certifiable visual loss in UK elderly