### Clue: Spot essentially going to obscure front of eye? (4)
### Answer: STYE 
 ### Explanation: Spot essentially going to obscure front of eye? (4)
**S**(po)**T** [*essentially going*] (i.e. the essence (middle) going) *to obscure* (make invisible) [*the start of*] (e)**YE **and &lit.