Presbyopia
👁️ Presbyopia – The “Aging Eye”
🔍 Definition
Presbyopia is the age-related loss of the eye’s ability to focus on near objects due to reduced elasticity of the lens and decreased function of the ciliary muscle.
📌 It's not a disease — it's a natural part of aging.
🧪 Pathophysiology
-
The crystalline lens becomes:
-
Less elastic
-
Thicker
-
-
The ciliary muscle becomes less effective at contracting
-
This reduces accommodation (the ability to change the lens shape to focus on near objects)
🔄 Accommodation normally allows the lens to become more convex for near vision, but this mechanism weakens with age.
📆 Onset
-
Typically begins around age 40–45
-
Progresses gradually until around age 65
⚠️ Symptoms
| Symptom | Description |
|---|---|
| Blurry near vision | Especially when reading or using a phone |
| Eye strain or headaches | After doing close work |
| Holding objects farther away | To see text more clearly (“short-arm syndrome”) |
| Difficulty in low light | Need for brighter lighting while reading |
🩺 Diagnosis
-
Based on history + symptoms
-
Confirmed with a refraction test (done by optometrists/ophthalmologists)
🧑⚕️ Treatment Options
| Type of Correction | Description |
|---|---|
| Reading glasses | For near vision only |
| Bifocal glasses | Distance + near vision in one lens |
| Progressive lenses | No visible line, smooth transition between distances |
| Multifocal contact lenses | For those who prefer contacts |
| Monovision contacts | One eye corrected for near, other for distance |
| Surgical options | Lens replacement (presbyopic IOLs), LASIK-based monovision |
🔬 Presbyopia vs Other Refractive Errors
| Condition | Problem | Correction |
|---|---|---|
| Myopia | Near vision good, distance bad | Minus (−) lenses |
| Hyperopia | Far vision better than near | Plus (+) lenses |
| Astigmatism | Blurred vision at all distances | Cylindrical lenses |
| Presbyopia | Age-related near vision loss | Reading or multifocal lenses |
🧾 Fun Fact
-
The word presbyopia comes from Greek:
-
Presbys = "old man"
-
Ops = "eye"
-
So literally, it means “old eye” — accurate and a little poetic!
Comments
Post a Comment