The Perfect Person-Visually

Understanding what defines a visually perfect person is a very useful tool in understanding how less perfect people work.  So here is an overview of normal development assuming people end up perfect every step along the way.
 

A perfect child (aren’t they all?)

Children are born farsighted (hyperopic), actually quite hyperopic, but as a child their focusing systems are quite large to compensate.  As they age their prescription quickly changes and becomes closer to plano (zero prescription).  By the age of five most children have hit plano (many children go beyond and become nearsighted today).  Prescriptions continue to change until the age somewhere between the age of eighteen and twenty-five.
 

A perfect adult approximately twenty-five years old

When the perfect adult looks at distance everything is clear without any effort.  The eyes are perfectly aligned and so they see things single (not double) their focusing system is completely relaxed and they are able to read 20/20 with either eye.  When it comes time for them to read, their focusing system kicks in and their lens expands.  Both eyes automatically turn in and align on the page.
 

A perfect adult approximately forty years old

Our focusing systems shrink with time so around the age of forty we all end up needing reading glasses.  A perfect individual at the age of forty will still see perfectly at distance without any effort.  But at forty they will start to notice they have to hold things further away to read.  They begin to have problems reading smaller print especially things like pill bottles and the newspaper.  Their eyes are still well aligned and once they have mild reading glasses (+1.00 usually to start) things are clear.
 

Sometime after forty

With time our focusing systems continue to get smaller.  Eventually the focusing system is effectively gone and usually people are satisfied up close with a +3.00.  At the same time cataracts begin to develop.  Cataracts often cause an increase in nearsightedness and can even induce astigmatism.  Our perfect person started without any prescription at distance but because of the cataracts he may become slightly nearsighted with some astigmatism.  We can correct this initial change in prescription with a pair of glasses and the patient may then switch to a pair of bifocals (because they still have problems up close too), however as the cataracts progress we will eventually be unable to clear the image.

We can remove cataracts with a surgery, which is done with an outpatient procedure and no longer requires thick glasses afterward.  Should someone desire they may chose a premium implant which can remove the necessity for reading glasses after the surgery.  Otherwise they will require reading glasses once again.

To review a couple key points about a perfect person:

• The eyes are always aligned without any effort at distance or up close

• Seeing clearly requires no effort from the focusing system at distance

• Even the perfect person needs reading glasses around forty

• Cataracts happen to everyone even perfect people
   

Understanding these key concept will help comprehension as we dig deeper into eye disorders.

“Dodge”

William Dodge Perry, OD

Falls Church VA

* I initially spelled the original title of this post as “The Pefect Person-Visually”.  Thank you to those that pointed this out.  It is a good reminder that nobody is perfect, esecially the author of this article. *