Poor vision and falls

Improving the vision of an older person should lower the likelihood of a fall. Randomised controlled trials suggest that this is often true, but not always.1 In fact, well meaning interventions can increase the risk of falls and changes should be made with care.

Poor vision increases the risk of falling.2 The person with impaired vision may not see hazards, particularly if peripheral vision is limited; may not see the poorly lit bottom step, particularly if depth perception is affected; and may not notice the change from carpet to slippery tiles, particularly if contrast sensitivity is impaired.

Multifocal and bifocal glasses further impair contrast sensitivity and depth perception.3 Multifocals also cause loss of acuity in the lower peripheral visual field owing to astigmatic aberration. Protective responses, such as grabbing a rail, may also be hindered by the peripheral prismatic effect. Use of these lenses is associated with an increased risk of falling.

In the linked randomised controlled trial (doi:10.1136/bmj.c2265), Haran and colleagues assess whether providing single lens distance glasses to regular …