Rods and Cones

Was doing some reading and something I read drove me to find out more about the eye and how it reacts to light. Came across a Tom Henderson who is a High School science and physics teacher with a rather extensive background in science and education. FYI, that’s important because I don’t have a rather extensive background in science and education.

But anyway, Tom goes on to explain that the eye is sensitive to a narrow band of frequencies referred to as the visible light spectrum. He goes into wavelengths, and the colors that different parts of the wavelengths correspond to, and a whole bunch of other stuff that I’ll just refer to as “oh…, that’s…interesting.” But here is the part of Tom’s lesson that clicked:

“Light which enters the eye through the pupil ultimately strikes
the inside surface of the eye known as the retina. The retina is lined with a variety of light sensing cells known as rods and cones. While the rods on the retina are sensitive to the intensity of light, they cannot distinguish between light of different wavelengths. On the other hand, the cones are the color-sensing cells of the retina. When light of a given wavelength enters the eye and strikes the cones of the retina, a chemical reaction is activated which results in an electrical impulse being sent along nerves to the brain."

Ahh, it’s all coming back to me now (not really…). Thanks, Tom for teaching me what I should have paid attention to in high school. This science lesson will come in pretty handy in a little bit.

So, back to what I was reading in the first place.

In Matthew 6:22-23, Jesus said:

22The eye is the lamp of the body. So if your eye is sound, your entire body will be full of light. 23But if your eye is unsound, your whole body will be full of darkness. If then the very light in you [your [r]conscience] is darkened, how dense is that darkness! (Amplified Bible Translation)

Here, Jesus is demonstrating His knowledge in what is known today as Ophthalmology, or according to the Greek, “the science of the eye.” These two verses sparked so much interest in me that I read and re-read them for about 3 days now, attempting to extract all Truth from them. So, three days, two verses, and one too many caffeinated drinks later, I think I’ve discovered the answer: Yes, leave omniscience to God.

But what He did reveal to me clarified my understanding of the two verses. In trying to see what Jesus was saying, we have to first understand the nature of Jesus’ language. He primarily spoke in parables, and these two verses are exactly that. A parable is basically an earthly story with a heavenly or spiritual meaning. So, this parable is referring to the actual science of the eye (a little more on this later).

In the beginning of verse 22, Jesus says the eye is the lamp of the body, or in other words the eye is the light source of the body. No other part of the body is sensitive to light but the eye. We can’t smell, taste, hear or feel light; we may be able to feel the heat generated by a light source, but we can’t feel light. Therefore, it is through our eyes that light enters the body.

Jesus goes on to say that if your eye is ‘sound’, or according to the original Greek word ‘Haplous’, If your eye is ‘whole’ or ‘functional’ your entire body will be full of light. The Greek word used here for ‘light’ is ‘Photeinos’ which means ‘well lit’. This statement from Jesus simply means with an eye that works, you can take in everything you see around you; your body is taking in light. In verse 23,Jesus says, If your eye is unsound, ‘Poneros’ in the Greek, meaning ‘of a bad nature or condition’, ‘in a physical sense: diseased or blind’. So if your eye is ‘blind’, you whole body will be full of darkness. The Greek word used here for darkness is, ‘Skoteinos’, which means just that, ‘covered in darkness’. We experience this kind of darkness every time we fall asleep.

Now, here is where things start to get interesting. Jesus is now going to convey the point of his super mini lesson on how the eye works. (Tom’s lesson was good, but Jesus used less words. Winner.) In verse 23 Jesus said, “If then the very light in you…” The Greek word for ‘Light’ used here isn’t the same Greek word for ‘light’ used in verse 22. Here, the Greek work is, ‘Phos’ which means:

- Of truth and its knowledge, together with spiritual purity associated with it
- The power of understanding

The Greek words are different simply because Jesus is now making the spiritual application to his scientific explanation. So, the actual Greek words used for ‘light’ and ‘darkness’ from this point on will have spiritual references.

So, in essence, Jesus, in verse 23 says, “If the knowledge of truth and spiritual things” in you is darkened…, the Greek word used here for ‘darkened’ is ‘Skotos’, which actually means:

‘Of ignorance respecting divine things and human duties and the accompanying ungodliness and immorality, together with their consequent misery in hell’.

No pressure here guys.

So, to include the Greek references, Jesus concluded his parable by saying, ”If the knowledge of truth and spiritual things in you is ignored (by not living them out), then how great is YOUR ignorance!”

Phew! Break time. Be back in 5. You might want to take a minute or two and re-read those Greek terms. I’ll talk about how Tom’s lesson ties in when I get back.

And we’re back. (Yes, I did take a real break.)

Now, as we finish up, I’m going to attempt to relate the magnitude of what Jesus is really saying, because it’s pretty off the wall. See, Tom said that when light enters the eye it strikes the retina which has two specific light sensing cells known as rods and cones. Think of ‘rods’ as the carnal mind, and ‘cones’ as the conscience within your heart. Both are sensitive to ‘Phos’ (Greek word for light), or knowledge, but rods (the carnal mind) can’t distinguish the relationship between spiritual purity and the power of knowledge . Cones (the conscience of the heart) can, and when it does, it sets off a chemical reaction (called conviction) which sends electrical impulse to the brain for the body to react accordingly.

So here’s the deal. Jesus is letting us know that just because we have a knowledge of spiritual things, doesn’t mean we have a relationship with Him, and we all know that a relationship with Jesus is necessary to preserve our life with Him. This is why He basically said those who think they have the knowledge of Truth better be sure they are not ignorant to its real purpose, which is to simply practice what we preach.

The Holy Spirit dwells within our hearts, and thank God He does, because in the busyness of every day, we need His help to consistently distinguish the relationship between spiritual purity and the power of its knowledge.