Sunday, January 26, 2014

Older adults and the loss of depth perception

Here is a graphic we made on older adults and the loss of depth perception.  Please share it to raise awareness.

Saturday, January 25, 2014

What is accomodative esotropia?

At our Vancouver eye clinic, we treat many patients with various types of strabismus.  One of them is accomodative esotropia.  Here is an excellent presentation by Professor Dominick Maino on accomodative esotropia:

Thursday, January 23, 2014

Eyes and aging - anisometropia 3D vision, binocular vision and increased fall risk

Eyes and ageing - depth perception and fall risk

A new study published in the journal, Optometry & Vision Science, has confirmed what many eye doctors with elderly patients already know: changes in the eyes as we age can degrade our ability to see depth (stereopsis) and in three dimensions (3D vision). That can contribute to blurry vision, eye strain and eye fatigue, and an increased risk of falls. Falls in the elderly are troubling because they can be the cause of brain injuries, broken bones or worse.

The new study looked at the incidence of a condition called anisometropia in elderly patients. Anisometropia is a condition in which the two eyes have unequal refractive power. That means that the focusing ability of the two eyes is unequal. Each eye is in a different state of myopia (nearsightedness) and hyperopia (farsightedness). The condition is characterized by blurry vision, double visoin, eye strain, eye fatigue, loss of depth perception. When anisometropia happens in children and infants, it can impair the development of normal binocular vision, which can lead to many learning and other problems.

Anisometropia is common in elderly people and it grows exponentially with age. The study found that significant anisometropia is at least 10 times more common in those older than 75 years than it is in children.  This is an alarming statistic and must be taken seriously by eye doctors.  At our Vancouver optometry clinic, we see large number of elderly patients because of our low vision practice and so we are always on the look-out for anisometropia.

The study's authors pointed out that the prevalence of anisometropia in US children is between 2 and 4% whereas data for those near 80 years old shows that 32% have 1.00 D or more anisometropia.

Related article:

When seniors loose depth perception and need to see a developmental optometrist
Thursday, June 28, 2012


Longitudinal Increase in Anisometropia in Older Adults

Haegerstrom-Portnoy, Gunilla; Schneck, Marilyn E.; Lott, Lori A
Optometry & Vision Science:
January 2014 - Volume 91 - Issue 1 - p 60-67